Marko Arnautovic scored twice in two minutes as West Ham came back from 2-0 down to earn a point against Brighton and end a run of the three consecutive defeats against the Seagulls.
The Austrian striker, who has been linked with Chelsea, proved his value again for the Hammers by turning around a game which came to life after a drab first half where Andy Carroll made his first start in exactly a year.
After Carroll was hooked at half-time, it was his replacement Lucas Perez, who failed to pick up Dale Stephens as the Brighton defender rifled the visitors ahead from the edge of the box.
Shortly afterwards, the Seagulls doubled their advantage when Shane Duffy peeled to the back post on another corner and controlled the ball on his chest before cleverly poking home.
Those were the eighth and ninth goals Brighton have scored from corners this season, but two further Manuel Pellegrini substitutions steered the game towards the Hammers.
First, Mark Noble chipped a lovely ball forward for Arnautovic to run onto before he hammered home from close range.
Then Michail Antonio cut the ball back from as close to the byline as he could get for Arnautovic to score his seventh goal of the season.
There were further chances for Antonio and Declan Rice to win it, but the point moved West Ham into the top half of the table.
When the disappointment of throwing away a two-goal lead subsides, Brighton will take solace in remaining unbeaten in three games over the festive period as they remain 10 points clear of the relegation zone.
Much of the attention prior to the match centred on Carroll, who made his first start in a exactly a year – when he scored twice to help the Hammers beat West Brom 2-1 – to freshen up his team.
But after only six appearances off the bench this season, the former Liverpool and Newcastle striker looked rusty as he miscontrolled the ball on several occasions.
A poor half was made worse when he was caught by a flailing elbow from Lewis Dunk that left the 29-year-old with blood running down his head.
And there was little link-up play between Arnautovic, 29, and Carroll, perhaps contributing to the fact that the Englishman did not emerge for the second half.
Perez dropped shorter to offer West Ham a different option up front but it was only after they conceded twice, and Noble and Antonio came on, that they really started to find their rhythm.