Liverpool, England, Feb 12: Steven Pienaar scored in his first game back at Goodison Park as Everton beat Chelsea 2-0 in the Premier League on Saturday.
The South Africa international, who rejoined the club last month on loan from Tottenham, opened the scoring in the sixth minute with a powerful shot into the roof of the net.
Chelsea, which had been unbeaten in 2012, had several chances to equalize through Daniel Sturridge and Frank Lampard but both missed the target.
Everton made the game safe when striker Denis Stracqualursi slotted the ball into the bottom right corner from the area after a pass from Landon Donovan sent him clear in the 71st minute.
Chelsea's defeat intensified the battle for fourth, the final Champions League place, dropping the west london side to fifth behind Arsenal after the Gunners beat Sunderland 2-1.
Chelsea manager Andre Villas-Boas, whose predecessor Carlo Ancelotti was sacked at the same ground last year, described the game as his side's worst display of the season.
"I think today was one of our worst games of the season, if not the worst," said Villas-Boas. "In our performance today we are short of anything positive.
"It is a difficult day for us, we take out a lot of negatives from this game."
The victory leaves Everton in 10th place in the league.