Ten-man Everton buried Manchester City's Premier League title hopes with a 2-0 win at Goodison Park.
Leon Osman's astonishing 30-yarder and Nikica Jelavic's stoppage-time clincher condemned City to their fourth straight defeat at Everton.
City had grounds for complaint when referee Lee Probert denied them a clear penalty in the 86th minute: Marouane Fellaini handled a Carlos Tevez shot over a yard inside the box, but Probert inexplicably awarded a free-kick.
However, Everton could point to Kevin Mirallas's first-half strike, wrongly disallowed for a phantom offside.
The result means Manchester United can go 15 points clear with nine games remaining if they beat bottom side Reading in the Premier League's late game.
Marouane Fellaini set the tone early for an aggressive game with a scything challenge on James Milner that earned his 10th booking of the season and a two-match suspension - he will miss games at home to Stoke and away at Tottenham.
It was the first yellow card of five in the opening period - Pienaar, Aleksandar Kolarov, Edin Dzeko and David Silva also drew referee Probert's wrath.
David Moyes's side started strongly and should have had the lead on 13 minutes when Mirallas smashed the ball into the roof of Joe Hart's net, only to be denied by an offside flag.
The decision met with few protests, but replays showed Mirallas was level with the last man Aleksandar Kolarov and the goal should have stood.
City came back and tested stand-in goalkeeper Jan Mucha with two shots from Dzeko and one from Carlos Tevez, but the Slovak held all three attempts with relative ease.
Then came a moment of genius that was more Rivelino than Leon Osman.
The England midfielder met Seamus Coleman's lay-off with his left instep, sending the ball on an extraordinary trajectory that started in the middle of the goal before swerving into the top-left corner.
Joe Hart could only stand and admire a goal of the highest quality - struck on his weaker foot.
It was just reward for an Everton side who responded to last week's Cup humbling by Wigan with a vibrant display.
City switched from three at the back to four, and back again, but there was no way through.
Mucha produced brilliant second half saves to deny Pablo Zabaleta and Milner - the latter coming after a delightful Dzeko lob had set up Tevez, and Mucha denied the Argentine before recovering to keep out Milner's effort.
Pienaar saw red on the hour mark, picking up his second yellow card for a rash tackle on Javi Garcia, but Everton's level of performance barely dropped.
City should have had a chance to level from the spot after Fellaini's handball, but it would have been a point they barely deserved.
And there was time for Jelavic to put an exclamation point on the victory in the third minute of stoppage time, curling a left-footer past Hart for his first league goal since December.
MAN OF THE MATCH
Seamus Coleman (Everton): A powerhouse display from the young Irish right-back. A constant menace going forward, and solid as a rock at the back.
EVERTON: Mucha 8, Coleman 8, Heitinga 7, Distin 7, Baines 7, Gibson 6, Osman 8, Pienaar 6, Mirallas 7, Fellaini 6, Anichebe 8. Subs: Jelavic N/A, Naismith 6.
MANCHESTER CITY: Hart 6, Zabaleta 7, Kolo Toure 6, Nastasic 7, Milner 6, Garcia 7, Barry 6, Kolarov 6, Silva 6, Tevez 6, Dzeko 6. Subs: Nasri 6, Sinclair N/A, Clichy N/A.