Swansea City twice came from behind to claim a 2-2 draw as Chelsea failed to start the defence of their Premier League title with a victory at Stamford Bridge.
The result comes as a blow to a side who were so impressive at home last season, but Jose Mourinho may well look back on the draw as a positive after Thibaut Courtois was sent off early in the second half.
From the early exchanges it was clear that Chelsea would not be gifted anything on the opening day as Bafetimbi Gomis came close to breaking the deadlock with a header which drifted just wide.
The French striker showed flashes of brilliance alongside moments of frustration, and many would have predicted that Swansea would live to regret another missed chance when he hesitated in the box to allow John Terry to recover before Gary Cahill cleared the danger off the line.
However, it was Chelsea who were in front midway through the first half when Oscar's inviting free kick from the left evaded everyone on the way to finding the bottom corner.
Swansea responded impressively to get back on level terms six minutes later through debutant Andre Ayew. Gomis had seen a powerful header saved by Courtois, but it was Ayew who reacted quickest to fire home at the second attempt after his initial effort was blocked.
Garry Monk's side had done enough to deserve the equaliser, but they were behind again just a few moments later as Chelsea benefited from a huge slice of luck when Willian's cross deflected off Federico Fernandez to leave Lukasz Fabianski helpless.
Short of the form which delivered the title last season, Chelsea continued to look sluggish early in the second half and they were given a scare when Jonjo Shelvey's corner struck the post.
A moment of concern soon became panic for the Stamford Bridge crowd as Gomis beat the offside trap to sprint clear before being caught by Courtois, who was immediately shown a red card for denying a clear goalscoring opportunity with the striker just inside the box.
Gomis stepped up to take on the responsibility from 12 yards and he made no mistake as substitute Asmir Begovic dived the wrong way and watched Swansea equalise for the second time.
Swansea continued to grow in confidence as Chelsea struggled to respond to the setback of being reduced to 10 men, and Begovic was twice forced to keep out efforts from the impressive Jefferson Montero.
It looked like there would be a winner for one of the sides, with Branislav Ivanovic heading just over from a Cesc Fabregas free kick shortly before substitute Wayne Routledge picked out Begovic's gloves with a tame shot.
Mourinho sent on debutant Radamel Falcao to partner former Atletico Madrid teammate Diego Costa, who played 90 minutes despite concerns about a hamstring problem, but neither forward could carve out an opening as both sides settled for a point in West London.