London - Arsenal lost ground on their rivals for a Premier League top-four place after a 0-0 draw at London Stadium on Wednesday that left West Ham United stuck in the relegation places.
The Gunners bossed possession but created few clear chances and are now seventh in the table, still below Burnley and now behind Tottenham Hotspur, having dropped seven points from their last three games.
West Ham almost won it late on but substitute Javier Hernandez saw his shot hit the underside of the bar, bounce downwards and stay out.
David Moyes' hosts were unchanged following Saturday's stirring derby win over Chelsea, but the home fans made hardly any noise at all in the opening stages as Arsenal stroked the ball about purposefully, with Alexis Sanchez firing straight at Adrian, the man currently keeping England number one Joe Hart on the bench.
Marko Arnautovic scored the only goal against Chelsea and had the ball in the net again in the 14th minute with a firm header from Arthur Masuaku's cross from the left, but was denied by a correct offside call.
Arsenal's Jack Wilshere, openly coveted by West Ham manager David Moyes as a January signing and making his first Premier League start in 577 days, was given a rare start but struggled to make an impact.
Sanchez was trying to make something happen however and saw an effort deflected behind. But when the corner was half-cleared to Alex Iwobi on the edge of the box he could not hit the target.
The recalled Nigerian did much better with his next effort, from closer range, but although it beat the goalkeeper it thumped back off the outside of the post.
Giroud fails to impress
Ainsley Maitland-Niles was making his first Premier League start for Arsenal and twice the 20-year-old left-back delivered enticing high balls towards Olivier Giroud only for the Frenchman, who had complained his World Cup place was in jeopardy because of a lack of first-team action, to fail to connect on both occasions.
That wasn't the case with Maitland-Niles' next cross though as Giroud leaped to launch a bicycle kick that smacked straight into Aaron Cresswell's face.
The half ended with West Ham's Manuel Lanzini in the book for hacking down Wilshere - and the second began with a great chance for Arnautovic, who scuffed over the bar.
Wave after wave of Arsenal attacks followed but when a deflection broke kindly for Mesut Ozil, the German poked across goal and wide.
Wilshere was becoming more and more influential, both on the run and through his passing but West Ham were defending in numbers and held firm.
Arnautovic had an effort cleared off the line by Nacho Monreal, but the Austrian had already been penalised for a push on Laurent Koscielny in the build-up.
Wilshere blazed Arsenal's clearest chance of the night over the bar soon after and, after the Gunners replaced Iwobi with Danny Welbeck, Sanchez forced Adrian into a diving save from a long-range free-kick.
Just a few seconds were remaining when Hammers skipper Mark Noble set up Hernandez, but although the Mexican striker's shot had the beating of Cech, it hit the bar.