Wojciech Szczesny 6 - couldn't really do much with the first goal, somewhat questionable and decision making on the second goal, but it was an improvement on the midweek game against Galatasaray.
Calum Chambers 5 - struggled to cope with Eden Hazard, was booked and can count himself lucky to have stayed on after a foul on Andre Schurrle. His yellow card means he's now suspended for the Gunners' next game.
Laurent Koscielny 5 - another player who was made a fool of by Hazard, Koscielny lunged in to concede the penalty and couldn't recover from there.
Per Mertesacker 6 - was fairly solid and kept Diego Costa quiet for most of the game, but was found wanting for Costa's goal, barely even making an effort to track the Spanish hitman.
Kieran Gibbs 7 - continues his strong start to the new season with another energetic display down the left hand side, and shackled Andre Schurrle well.
Mathieu Flamini 7 - given his usually poor displays, Flamini wasn't too bad today. With five tackles, Flamini was certainly robust in front of the back four, whilst his passing was decent too.
Jack Wilshere 7 - was neat, intricate and looked to create in the final third. Worked as hard as ever, but his poor first touch let him down in front of goal in the first half.
Mesut Ozil 5 - started on the right hand side again for some bizarre reason, and was predictably quiet, often ponderous in possession and looking for a second more time than he had.
Santi Cazorla 7 - bright, lively and always looked to spring in attack. Was strangely substituted for Alex Oxlade-Chamberlain in the second half despite being one of Arsenal's better players.
Alexis Sanchez 6 - Was unfortunately involved in the incident which led to Thibaut Courtois' substitution, but was really quiet throughout before being replaced by Lukas Podolski.
Danny Welbeck 6 - couldn't follow up his midweek hat-trick against Galatasaray today, and didn't even attempt a shot
Alex Oxlade-Chamberlain 6 - came on with 20 minutes to play and had an impressive driving run into the Chelsea box but couldn't haul Arsenal back into the game.
Tomas Rosicky and Lukas Podolski also came on, but didn't have enough time to make an impact.