Canada international Scott Arfield's 90th-minute winner earned Burnley an improbable 2-1 victory over a dominant Everton at Turf Moor on Saturday.
Everton impressed in a 1-1 draw with Manchester City last weekend and were looking to close to within a point of Pep Guardiola's side in the Premier League table.
But after Yannick Bolasie had cancelled out Sam Vokes's opener for Burnley, Arfield slid home at the death to lift Burnley three points clear of the relegation zone and prevent Everton breaking into the top four.
It was only a second win in seven league games for Sean Dyche's Burnley as Ronald Koeman's Everton registered a fourth successive match without victory.
Koeman made two changes to his starting XI, recalling Ross Barkley and bringing in Kevin Mirallas, who warmed home goalkeeper Tom Heaton's palms with an early effort following a Bolasie surge.
Barkley was left on the bench for the draw at Manchester City and he signalled his determination to prove his worth to Koeman with a powerful strike that Heaton pushed away.
Everton totally dominated the opening stages, seeing over 70 percent of possession in the first half hour.
But it was Burnley who took the lead, six minutes before half-time, after a blunder by goalkeeper Maarten Stekelenburg.
The Dutch international, who saved two penalties at City, could only palm Arfield's tame poked shot into the path of Wales striker Vokes, who gleefully tucked the ball into an untended net.
After Heaton had saved comfortably from Barkley, Bolasie equalised just before the hour, pinching the ball from team-mate Lukaku and slamming home his first Everton goal.
Everton had all the momentum and Burnley spent the last half an hour on the ropes, Michael Keane intervening to deny Lukaku and Heaton swatting away a cross from Bolasie as Lukaku closed in.
But with stoppage time approaching, Johann Berg Gudmundsson's shot came back off the bar and Arfield pounced on the rebound to earn the hosts a smash-and-grab success.