Chris Hughton's side couldn't maintain their 100 percent home record, but they still moved two points clear at the top as second placed Middlesbrough lost 2-0 at Reading.
The Seagulls, seeking a fourth win in five home games, suffered an early shock when striker Joe Mason put Cardiff ahead after five minutes.
Full-back Scott Malone got free down the left and his accurate low cross was converted from three yards out by Mason for his fifth goal of the season.
That was the first time that Brighton had gone a goal down in a league game this season, but the hosts equalised seven minutes before the interval through Dale Stephens, who fired home from 15 yards following a cross by Beram Kayal.
Middlesbrough's run of five successive league wins came to an end at third placed Reading.
Aitor Karanka's team were completely outplayed by the hosts, who secured their fifth league win in six matches with a goal in each half.
Danny Williams opened the scoring with a header after only 15 seconds and a Nick Blackman penalty two minutes from time settled it.
Demarai Gray underline his potential as Birmingham climbed to fourth place with a 2-0 win at Leeds.
When Gray's goal arrived in the 31st minute the chance was presented to him on a plate.
A mix-up between Leeds duo Liam Cooper and Sol Bamba left Gray with time and space to lash past Marco Silvestri for the young forward's first goal of the season.
Substitute Jacques Maghoma then raced through to score a fine individual goal in the 90th minute that left Leeds without a home win for seven months.
A first-half goal from Abel Hernandez was enough to earn fifth placed Hull a 1-0 victory and leave 10-man Nottingham Forest frustrated at the City Ground.
There were suspicions of offside when the forward bagged his fifth goal of the campaign in the 41st minute, after Sam Clucas had provided the flick-on from a Shaun Maloney corner.
Jay Emmanuel-Thomas smashed home a stoppage-time winner as QPR eased the pressure on manager Chris Ramsey by beating Bolton 4-3 at Loftus Road.
Wolves striker Benik Afobe grabbed two goals in a 3-0 win over Huddersfield at Molineux.
Jordan Rhodes continued his fine goalscoring form and bagged a brace as Blackburn defeated his former club Ipswich 2-0 at Ewood Park.
Elsewhere, Derby defeated Brentford 2-0, Sheffield Wednesday beat Preston 3-1 and Bristol city drew 1-1 with Milton Keynes Dons.Â