Alex Song headed in a late winner Saturday to give Arsenal a 1-0 win over last-place West Ham and keep pace with Premier League leader Chelsea.
The Cameroon midfielder nodded home from close range from Gael Clichy's 88th-minute cross to deny the Hammers a point at Emirates Stadium.
Arsenal had earlier hit the bar twice, through Samir Nasri and substitute Theo Walcott. West Ham goalkeeper Robert Green also produced a number of saves to thwart the hosts.
''It's a relief when you win with two minutes to go,'' Arsenal manager Arsene Wenger said. ''It was difficult to get in the flow in the first half but we kept the structures of our game right, we kept trying to be intelligent and we got the goal.''
Arsenal remains five points behind Chelsea, which beat Blackburn 2-1, and Wenger said his players' growing maturity marks them out as title challengers.
''You could see that maturity in this game - when it doesn't work for us, I believe the players remain calmer than before,'' Wenger said. ''I believe we have a good chance (for the title) but we have to show consistency. And we still need to step up a gear.''
West Ham stayed rooted to the foot of the table on just six points, with the loss increasing the pressure on manager Avram Grant.
''We are not in a good situation in the league but we are in a good situation with our performances,'' Grant said. ''We are playing good football and the team has a very good fighting spirit. ''We aren't in November yet. There are six or seven months until the end of the season.''
Buoyed by consecutive away wins - 3-0 against Manchester City in the league and 4-0 over Newcastle in the League Cup - Arsenal started well but lacked its usual spark going forward early on.
Andrey Arshavin smashed a shot wide after exchanging a one-two with Marouane Chamakh before Song headed just over.
West Ham looked most dangerous when sending set-pieces into the box although midfielder Mark Noble went a more direct route, dispossessing Denilson and rifling a 22-yard effort straight at goalkeeper Lukasz Fabianski.
The final 20 minutes of the half belonged to Arsenal but Green was in inspired form.
The much-maligned England goalkeeper clawed away a close-range shot from Arsenal captain and playmaker Cesc Fabregas in the 25th minute and then got down well to keep out a hard drive from Song. In the last act of the half, Green tipped over a header from Sebastien Squillaci.
Fabregas, who has yet to get into full stride this season because of a number of injury problems, was well shackled by West Ham midfield anchor Scott Parker in the first half, which helped to restrict Arsenal's attacking rhythm.
Wenger revealed afterwards that Fabregas had been struggling with a hamstring injury throughout the game.
''For me, he played a little within himself,'' Wenger said. ''He had a little tension in his hamstring and at halftime I had a hesitation to take him off. I was going to give him 10 to 15 minutes but he got better and better.''
A late tackle by Parker on Denilson minutes after the restart riled the home fans, who were soon up on their feet when Nasri's 40-yard free-kick smashed against the bar and rebounded over.
Green comfortably saved headers by Fabregas and Chamakh as Arsenal dominated possession and the home side went even closer in the 72nd when Walcott ran onto a fabulous through-ball by Fabregas but hit an angled shot against the post.
Another Walcott effort was turned away by Green in the 84th and the goalkeeper denied Fabregas with four minutes left.
