A sublime performance from Albion saw them stun Chelsea with a 2-1 triumph at Kingsmeadow.
Chelsea came out of the blocks quickly and opened the scoring after just five minutes. Sam Kerr looped a header over Megan Walsh from Erin Cuthbert’s pinpoint delivery from a corner.
The lead lasted just two minutes, though, as Brighton equalised from a corner of their own. Aileen Whelan thundered a header past Carly Telford from Megan Connolly’s centre.
Chelsea moved the ball sharply as they looked to restore their lead as the snow swirled around Kingsmeadow, but Brighton stuck to their task well and went in all square at the break.
With Hope Powell’s Seagulls staying compact and battling hard, Emma Hayes turned to her bench 10 minutes into the second half.
Record signing Pernille Harder almost put the Blues ahead after 75 minutes but she could only hook the ball onto the right-hand post after good work down the left from Jonna Andersson.
Brighton won a corner from the resulting attack and took a shock lead when Telford could only palm Connolly’s inswinging corner into her own net in the 77th minute.
Chelsea piled on the pressure in the closing stages but Brighton’s heroic back-line stood firm and they headed back to the south coast with a hard-fought three points.
“It was a demanding, tough game,” said Albion coach Powell. “We had to be disciplined with hard work and good effort and if you do those things you give yourself a chance of winning the game.
On the winning goal, she added: “I’ll take some luck against a side like Chelsea – you take all the luck you can get.”
In a long and impressive career in the game, former England boss Powell said the win over the champions was “up there”.
“They’re a top, top team. I’m sure it will sink in later,” she said. “Chelsea’s run had to end at some point and I’m just glad it was us. The most important thing was the three points.”
The Blues stay top of the table on goal difference but have a game in hand on United.