Thibaut Courtois was sent off as Chelsea started the defence of their Premier League title with a 2-2 draw at home to Swansea City.

Courtois was shown a straight red card early in the second half for bringing down the impressive Bafetimbi Gomis, who beat Asmir Begovic with the resulting penalty to deny the champions all three points.

Chelsea had led at half-time courtesy of a somewhat fortuitous Oscar free-kick and a Federico Fernandez own goal either side of a composed finish from Swansea new boy Andre Ayew on his Premier League debut. 

Gomis had a goal ruled out for offside after his spot-kick, but Swansea had to settle for a point - which was the least they deserved for an impressive display as Chelsea boss Jose Mourinho was unable celebrate signing a new four-year deal with a win.

Begovic is now set to make his first start for Chelsea in a mouth-watering clash with Manchester City next weekend, with Courtois suspended.

Diego Costa was passed fit to lead the Chelsea line despite concerns over his troublesome hamstring, while Ayew was the only Swansea new boy in Garry Monk's XI.

Gomis looked poised to open the scoring after 14 minutes when he cut inside Gary Cahill after racing onto Jonjo Shelvey's incisive pass, but John Terry denied him with a crucial last-ditch tackle.

Costa wanted a penalty when he went down under a challenge from Fernandez, but referee Michael Oliver correctly pointed for a corner as the Swansea defender got a touch of the ball.

Chelsea looked dangerous going forward and they were in front after 23 minutes when Oscar's free-kick came through a crowded penalty area and found the far corner of the net.

The champions' lead lasted only six minutes, though, as Ayew made an immediate impact in English football.

Courtois produced an outstanding save down to his right to keep out Gomis' downward header, but Ayew showed great composure and skill to drag the ball back before firing home from close range after his initial follow-up effort was blocked by Cahill.

Swansea had barely finished celebrating when they fell behind for a second time and there was a huge slice of luck for Chelsea, as Willian's attempted cross struck Fernandez and looped inside the far post.

The visitors again responded well as a Shelvey corner hit the post early in the second half and they were back on level terms with a numerical advantage 10 minutes after the break.

Courtois was given his marching orders after racing out to upend Gomis as he got on the end of another fine Shelvey pass, and the French striker picked himself to send Begovic the wrong way from the spot. 

Swansea were now dictating the game and Begovic twice denied Jefferson Montero before Gomis' close-range effort was ruled out for offside.

Lukasz Fabianski kept out Eden Hazard's effort at his near post before Radamel Falcao came on as a late substitute but neither side could come up with a winner, with Chelsea at least ensuring no team has ever lost their first game of a Premier League season as reigning champions.