Diego Costa scored twice as Chelsea were held in a pulsating clash at the Liberty Stadium.
The Spain striker, playing his usual role of pantomime villain, opened the scoring with a precise first time finish from the edge of the box after being teed up by Oscar.
Thibaut Courtois gave away a penalty after a reckless attempt to close down Gylfi Sigurdsson. The Icelandic midfielder fired the spot-kick high into the net to bring his team back level before Leroy Fer put the Swans in front after stealing to ball from Gary Cahill. Costa delivered a crucial equaliser with a well executed overhead kick.