Costa winner for Chelsea dents title hopes of 10-man Arsenal

Diego Costa dealt Arsenal’s title aspirations a huge blow as his first half goal was enough to earn Chelsea a 1-0 win over the 10-man Gunners at the Emirates.

With Jose Mourinho departed, this was supposed to be the Gunners' big chance to prove that they are ready to secure their first Premier League crown in 12 years but, right form the off, Chelsea dominated.

Cesc Fabregas and Diego Costa’s every touch was greeted by a chorus of boos, but the pair excelled throughout, and showed Blues fans that they can recapture their grandeur of last season.

Costa’s first major contribution was to draw the tackle from Per Mertesacker that earned the rangy German defender a straight red card, after being deemed to be last man. Then, with the Gunners still trying to regroup, Costa darted across substitute Gabriel to fire his side in front.

After the interval, the match became an eerie throwback to a Mourinho-esque defensive display, as Arsenal were frustrated by some solid rearguard action as Chelsea held on for the victory.

The script suggested that this was the day the Gunners would secure a long-awaited victory over Chelsea, with the Blues in such disarray, but once again in this fixture, Arsenal came unstuck, and remain in third after missing the chance to return to the top of the table, while Chelsea’s unbeaten run since Mourinho’s departure goes on.

15’ - CHANCE! First real chance of the match. Willian arrives late at the back post, volleys at goal, his effort is blocked, he reacts first to the loose ball, prods at goal, but Cech is down to smother.

18’ - RED CARD FOR PER MERTESACKER! The German is deemed to be last man when challenging Costa. Seems to be the right call. Perfect pass from Willian was taken in his stride by Costa, who crossed Mertesacker's outstretched leg.

23’ - GOAL! Arsenal 0-1 Chelsea. It had to be him. Classic centre-forward's goal from Costa breaks the deadlock. What a turn up for the books here. Branislav Ivanovic whipped a superb cross into the near post, but it was all about Costa's timing, as he darted in front of Gabriel and side-footed home.

44’ - OFF THE LINE! Nacho Monreal gets back on the line to head Ivanovic's header from the resulting corner away from underneath his crossbar. Cech may have been able to get across, but the full-back was taking no chances.

56’ - Alexis Sanchez returns to the fray for Arsenal, and boy do they need him! Campbell makes way.

63’ - CHANCE! Well, several in fact! Thibaut Courtois gets lucky after flapping at a free-kick, it hits Ivanovic, falls to Koscielny, whose effort is blocked, before Kurt Zouma blocks another goalbound strike from Flamini. Frantic stuff.

88’ – BLOCKS! Frantic stuff from Chelsea. They are throwing their bodies in front of everything. Ramsey breaks into the box, but again he is dispossessed.

Arsenal have now failed to score in their last six Premier League matches against Chelsea, equalling their longest run without a goal against a specific opponent in the Premier League (also six against Liverpool between 1997 and 2000).

Chelsea keep three consecutive Premier League away clean sheets for the first time since a run of four in a row from December 2013 to February 2014.

Chelsea are now unbeaten in nine league matches against Arsenal, stretching back to the 5-3 home defeat on 29 October 2011. It extends their longest top flight unbeaten run versus the Gunners.

Chelsea become the first visiting team to win four PL matches at Emirates Stadium (Aston Villa and Manchester United both 3).

Are Arsenal going to blow their title chances once again? We have been here before. Arsenal have looked like winning their first Premier League title since 2004 on numerous occasions since, but they have faltered when it really mattered. This season, everything has fallen in the Gunners’ favour, with Manchester City plagued by inconsistency, Manchester United’s fall from grace getting more embarrassing by the week, and Chelsea’s meek title defence allowing a new suitor to make the quest for the top-flight crown. Yet, against their old foes, the Gunners have slipped up once again. City have too much quality to keep giving them chances. The biggest test is to come, as recovery from such a debilitating defeat could be make or break for Wenger’s men.

Cesc Fabregas. Not the candidate many will have selected pre-match having disappointed for much of this campaign, but the Spaniard controlled the game from start to finish, made five times the amount of successful tackles as normal, and looked pumped right from the off. If Chelsea can keep Fabregas as riled as he was at the Emirates, then a late assault on the top four is not out of the question.

Arsenal: Cech 7, Bellerin 6, Mertesacker 3, Koscielny 6, Monreal 4, Flamini 5, Ramsey 5, Campbell 4, Ozil 5, Walcott 5, Giroud 5... Subs: Gabriel 5, Oxlade-Chamberlain 5, Sanchez 6.

Chelsea: Courtois 6, Ivanovic 7, Zouma 8, Terry 8, Azpilicueta 7, Mikel 8, Matic 8, Willian 8, Fabregas 9, Oscar 7, Diego Costa 8... Subs: Hazard 6, Remy 6.