Arsenal came from behind to end their nine-match winless streak as Freddie Ljungberg enjoyed his first victory as interim manager at the expense of his former club West Ham.
Eighteen-year-old Gabriel Martinelli marked his full Premier League debut by side-footing an equaliser which cancelled out Angelo Ogbonna’s deflected first-half opener at London Stadium.
Within nine minutes, Nicolas Pepe had curled a magnificent second into the top corner and Pierre-Emerick Aubameyang fired in a third.
The salvo turned the game on its head and piled the pressure on West Ham boss Manuel Pellegrini, whose side have taken four points from their past nine league games and conceded three times in three successive home games.
The Hammers remain a point above the relegation zone in 16th and face a trip to third-bottom Southampton on Saturday. Arsenal move up two places to ninth.
Arsenal recover from dismal start
Arsenal’s victory was all the more remarkable because until Martinelli added to the seven goals he has scored in cup competitions this season, the visitors had been utterly woeful.
Club officials had spoken before kick-off about the improved atmosphere triggered by Ljungberg’s appointment as Unai Emery’s replacement but it appeared this game would end in frustration, just as the previous two had done under the Swede.
The visitors were bereft of confidence and mild boos from the travelling support accompanied the end of a first half in which their side failed to have a shot on target and went behind when Ogbonna’s header bounced in off Ainsley Maitland-Niles.
True, they did not have much luck. Hector Bellerin was injured in the warm-up and when Kieran Tierney was helped off in obvious pain with a shoulder injury sustained in a seemingly innocuous tangle with Michail Antonio, Ljungberg had lost both his first-choice full-backs in the space of half an hour.
Nevertheless, it was pitiful stuff and when Aubameyang surged down the right wing and sent over a cross that flew over everyone and straight out for a throw-in on the other side of the pitch, it was symptomatic of a club apparently heading nowhere fast.
‘Nerveless’ Martinelli rewards Ljungberg’s faith
It was 1977 when Arsenal last went 10 matches without a win. With an away Europa League game against Standard Liege followed by a home encounter with Manchester City to come, at the interval it was not beyond the realms of possibility that the 12-game barren sequence from 1974 was going to be threatened.
With Alexandre Lacazette and David Luiz on the bench, it was two of Arsenal’s most inexperienced players who sparked the change in fortune.
Ljungberg had obviously seen enough of Martinelli in two substitute appearances to trust the Brazilian with his first league start. The reward was a nerveless finish when his side needed it most. Sead Kolasinac provided the cross but there was still a lot to do for the Brazilian, who steered a first-time effort into the corner.
Emery paid a club record £72m for Pepe in August. With one league goal all season, the Frenchman has not really lived up to his billing but his goal here, a curling shot into the right-hand corner of David Martin’s net, was perfect in its execution.
Aubameyang made certain of a win few would have anticipated 10 minutes earlier when his clinical finish took his tally for the season to 13. It disguised the fact he had been a virtual spectator for the first hour.
At the final whistle, Ljungberg ran to applaud the visiting fans, knowing he had given his own chances of replacing Emery a significant boost.
What now for the unhappy Hammers?
When they beat Chelsea 1-0 nine days ago to end their own winless sequence, it appeared West Ham were on an upward curve.
The combination of boos and thousands of empty seats that accompanied the final whistle on Monday underlined the truth of the matter.
West Ham are perilously close to dropping into the relegation zone, something the club cannot countenance after moving to the 60,000-capacity London Stadium.
Even if Pellegrini survives this defeat, if West Ham lose again at Southampton on Saturday the calls for his dismissal will become piercingly loud.
This was the third home game running in which they had conceded three goals.
The Hammers were not particularly convincing when they were in front. Once they lost the advantage, the lack of confidence so clear in Arsenal’s play transferred to theirs.
Record signing Sebastien Haller was left on the bench and even when he was introduced 20 minutes from time, he made no noticeable impact.
Man of the match: Gabriel Martinelli (Arsenal)
‘Like a Duracell battery’ – what they said
Arsenal interim boss Freddie Ljungberg told BBC Sport: “The players have belief and tried to move the ball with more tempo. West Ham got tired.
“The players ran their socks off and fought. I believe in them. When I could see them put their shift in, I could see the quality. I thought ‘it is here for the taking’.
“Martinelli did amazingly. He is like a Duracell battery, he keeps going. Laca [Alexandre Lacazette] is a tremendous player but I had to make a tough decision.”
West Ham manager Manuel Pellegrini told BBC Sport: “For 60 minutes there was just one team on the pitch. But football can be like this.
“We made mistakes in moments of defending. The problem was a lack of patience and quality to decide the game with a second goal and we made important mistakes in defence.
“The pressure for me is exactly the same if we win or lose. When you don’t have results things are more difficult. If I had not seen the team play the way they did in the first 65 minutes, I might have doubts [about his ability to turn things around].
“After Southampton at the weekend we have a break. We must try to recover as quickly as we can and we must try to win those three points.”
Rare Arsenal recovery away from home – the stats
- West Ham have lost three in a row at home in the Premier League for the first time since August 2015.
- Arsenal came from a half-time losing position to win a Premier League away game for the first time since October 2011 (5-3 v Chelsea).
- Gabriel Martinelli is Arsenal’s fourth-youngest scorer in the Premier League (18 years 174 days), after Cesc Fabregas, Serge Gnabry and Alex Oxlade-Chamberlain.
- Arsenal’s Pierre-Emerick Aubameyang has been involved in 12 goals in his past 11 Premier League London derbies (nine goals, three assists).
- Since his Premier League debut in February 2018, Aubameyang has scored 43 goals in the competition, a joint-high along with Jamie Vardy.
Arsenal conclude their Europa League group phase campaign at Standard Liege on Thursday (17:55 GMT), still needing a draw to be sure of qualification before entertaining Manchester City at Emirates Stadium in the Premier League on Sunday (16:30). West Ham visit Southampton on Saturday (17:30).
West Ham manager Manuel Pellegrini took responsibility as his side were bundled out of the Carabao Cup in humiliating fashion by League One Oxford United.
The Hammers arrived at the Kassam Stadium on the back of an outstanding win over Manchester United to reach the heights of fifth in the Premier League, but Karl Robinson’s side superbly outplayed and over-powered their illustrious opponents, who ended a complete shambles.
Oxford, currently 12th in League One, were high on confidence after a record-breaking 6-0 win at Lincoln City at the weekend and this was a famous and richly merited triumph.
“The whole team didn’t play well. Not only did we concede four goals, but we didn’t create too many chances,” Pellegrini said.
“We missed too many passes from the beginning and the responsibility is first on me because I picked the players, and second on the team that didn’t compete.
“It’s easy to say that we played very badly, but Oxford did everything they needed to win this game. They played with a lot of motivation, with desire and we didn’t play well.”
Both sides fielded much-changed sides and the only surprise was West Ham actually survived for so long before conceding after 55 minutes when Oxford central defender Elliott Moore shot across Roberto.
Oxford, who missed clear chances in the first half through Cameron Brannagan and Anthony Forde, almost increased their lead immediately as Roberto saved brilliantly from Jamie Mackie.
But there was no escape for West Ham as substitute Matty Taylor turned in Mark Sykes’ cross with 19 minutes left.
Substitute Tariqe Fosu, a hat-trick hero at Lincoln City, raced clear from the halfway line to score with great composure after 84 minutes to extinguish any hopes of a West Ham comeback.
The agony was not over yet for West Ham boss Pellegrini and his abject side as Shandon Baptiste deservedly capped a man-of-the-match showing with a classy fourth.
Oxford host fellow League One side Sunderland, who won 1-0 at Sheffield United, in the fourth round in the week commencing 28 October.
“Looking at the scoreboard – 4-0 against West Ham and a very strong West Ham – this will probably go down as one of the biggest results at the Kassam in recent years,” Oxford boss Robinson said.
Humiliation for West Ham and Pellegrini
The EFL Cup represented a realistic opportunity for West Ham to win a trophy, but Pellegrini risked this shock by making nine changes, leaving out danger men Sebastien Haller and Felipe Anderson.
He paid the price as the Hammers produced a desperate display, much to the annoyance of the fans who packed one corner of this three-sided stadium.
West Ham were lethargic, off the pace and apparently complacent as they were hustled out of their stride as the track-suited Pellegrini failed to inspire his team.
He kept Haller back until they were a goal down but by then the momentum was flowing inexorably in the direction of Oxford, who should have inflicted even heavier punishment as they ran riot towards the end.
Jack Wilshere wasted an opportunity to stake a claim as he was over-run by the energy of Baptiste. Wilshere looked a spent force in contrast.
It was reminiscent of West Ham’s loss at League One AFC Wimbledon in the FA Cup fourth round last season as they lacked heart and stomach for the fight, surrendering without suggesting for one moment they would get back into this game once Oxford went ahead.
West Ham have shown signs of stability and improvement in the Premier League, and this was an altered line-up, but their performance was inexcusable and all the plaudits must go to the underdogs.
“I thought it was a poor performance from everyone,” said Hammers captain Zabaleta.
“We feel sorry about the performance tonight and sorry to the away fans who came to the game. It was just a bad night.”
Oxford’s glory night
This competition gave Oxford the greatest day in their history when they beat QPR at Wembley in 1986 – and this is a night that will also live long in the memory of the jubilant fans.
West Ham made changes but, for context, Oxford manager Robinson also made six changes and his team dealt much better with those alterations.
Oxford were in command from the first whistle, sensing immediately that West Ham were not in the right frame of mind to face a lower league opponent determined to inflict a shock.
Robinson may have feared the first-half misses from Brannagan and Forde may haunt them, but they won at a canter and it would not have been unfair had they enjoyed an even greater victory margin.
Oxford have now scored 10 goals without reply in their past two games and this scoreline was a more than accurate reflection of the gulf between the two sides.
Baptiste was outstanding in midfield, the veteran Mackie was a threat throughout and it is huge credit to Robinson and his players that they never took a backward step once Moore put them ahead 10 minutes after the break.
Oxford continued to be bold and go in search of goals, and the celebrations on and off the pitch at the final whistle were fully deserved.
This was a night of shame for West Ham, but it would be an insult and injustice to downgrade the quality of Oxford’s performance that brought this outstanding victory.
“We had the belief in ourselves that we could get a result,” Robinson said. “I’m over the moon for the fans and the players.
“It’s about the players, about the fans and about the community of Oxfordshire and the big thing for me now is the people who came here for the first time in a long time, that they buy a ticket and come on Saturday [for the league game against Gillingham].”