Arsenal got their top four hopes back on track with a 2-0 win over Chelsea.

The home side capitalised on their early dominance when Alexandre Lacazette killed the ball with a remarkable first touch from Hector Bellerin’s cross and danced his way past Pedro and Marcos Alonso before firing the ball into the top corner at the near post.

Arsenal doubled their advantage just before half time as Laurent Koscielny beat Chelsea’s offside trap and met Sokratis’ lofted ball and beat Kepa Arrizabalaga directing the ball in with his shoulder.

Alonso, who scored the winner in a 3-2 thriller when the two sides met at Stamford Bridge on the second week of the season, almost pulled a goal back for the visitors on the stroke of half time but his header from Pedro’s corner bounced off the post.

Arsenal suffered a blow in the second half when Hector Bellerin was stretched off with a knee injury which could see the Spaniard on the sidelines for a long spell.

Chelsea controlled the ball for the majority of the second half but struggled to break down a dogged Arsenal defence as Koscielny and Sokratis proved to form a formidable partnership to earn the Gunners a rare clean sheet.

Takeaways from the game

Front three pressing key for Arsenal

Unai Emery set his team up with Aaron Ramsey playing up alongside Pierre-Emerick Aubameyang and Lacazette. Their pressing in the first half was relentless as Ramsey pressed from the front to limit the supply to Jorginho, who so often dictates the play for Chelsea.

Arsenal executed their manager's gameplay to a tee in the first half as Lacazette’s unremitting work rate provided the Gunners a constant focal point in attack. The Frenchman seemed to relish in the big game atmosphere having scored an exceptional goal to give Arsenal an early lead.

Aubameyang almost reaped the rewards for his pressing as his stray touched allowed him to sprint on to the ball against  Antonio Rudiger, and the Gabon striker was unlucky not to have got on the scoresheet as his poked effort was denied by Kepa.

Captain Koscielny leads by example

Koscielny has struggled since returning from his ACL injury which kept him out for nine months in a shaky Arsenal defence, however, the Arsenal skipper turned back the clock today with an outstanding performance.

The French centre back didn’t put a foot wrong up against a pacey attack as Maurizio Sarri lined up with Pedro, Eden Hazard and Willian. Chelsea clearly lacked an aerial presence up front until Olivier Giroud was brought on with just over 20 minutes remaining.

However, the former Arsenal striker was unable to make too much impact as both Sokratis and Koscielny held firm and battled hard to earn their side a clean sheet.

Top four race wide open

Had Chelsea come away from the Emirates with three points, they would have been nine points clear of both Arsenal and Manchester United and in a commanding position to finish in fourth place.

However, in a must-win game for the Gunners, they kept their top four hopes alive with an imposing victory with 15 Premier League games still to play.

Competition for a top-four place has become fiercely competitive with a rejuvenated Manchester United under Ole Gunnar Solskjaer posing a serious threat to Arsenal and Chelsea despite their abysmal start to the season under Jose Mourinho.

However, a run of five consecutive wins, including an impressive 1-0 win at Wembley against Tottenham Hotspur, has seen the Red Devils pull level on points with fifth-place Arsenal.

Arsenal and Manchester United meet each other in the FA Cup fourth round at the Emirates on Friday evening as Unai Emery is set to manage his first home game in the FA Cup.