Palace went 1-0 down in the first half when Nathan Delfouneso converted
The result left Palace three points adrift of leader Cardiff City, which beat Blackburn Rovers 4-1 the previous night.
Leicester City dropped to fifth in the table after needing a last-minute equaliser from
The Tykes arrived at the
The travelling fans were ready to toast victory, but Vardy turned home
Middlesbrough took advantage of Leicester's slip-up as it moved up to third with a nervy 3-2 win at Peterborough United.
Gayle then gave the bottom side a surprise second, but
Kazenga Lua Lua stepped off the bench and earned fellow play-off hopeful Brighton & Hove Albion a valuable point in a four-goal thriller at Charlton Athletic.
Nottingham Forest leapfrogged local rival Derby County in to ninth with a 2-0 home win over Burnley thanks to goals from
At the other end of the table,
City, which started just one place above the Owls in the table, then stole all three points with Adomah's stunning set-piece that will pile more pressure on Wednesday boss
Eagles then missed a chance to put the game to bed from the penalty spot and Vaughan made him pay by finishing
DJ Campbell scored twice and
Wolverhampton Wanderers edged past midlands neighbour Birmingham City 1-0 at Molineux.
Wolves was winless in six in front of its own fans going into the derby clash, a run stretching back to the start of September, while it had lost its last two on home soil.
But that sorry streak came to an end courtesy of Marlon King's 34th-minute own goal, the Birmingham striker slicing past Jack Butland when attempting to clear Bakary Sako's drilled free-kick at the front post.