Wolverhampton Wanderers' Pedro Neto struck a stoppage-time winner as they came from behind to beat Chelsea 2-1 in the Premier League on Tuesday.
Frank Lampard's visiting side had the better of the first half at Molineux and centre-half Kurt Zouma powered a header against the bar just before the break.
In-form French forward Olivier Giroud then fired Chelsea ahead in the 49th minute, meeting a Ben Chilwell cross with a superb angled volley at the near post that goalkeeper Rui Patricio was unable to stop cross the line.
But Wolves drew level in the 66th minute when Daniel Podence cleverly created space for himself in the box and then drove a slightly deflected shot past keeper Edouard Mendy.
Wolves were then awarded a penalty, 10 minutes from the end, when Pedro Neto went down inside the box as he was approached by Reece James but the decision was overturned after a VAR review showed there had been no contact.
But Portuguese forward Neto decided the encounter late in added time when he finished off a counter-attack, running at Kurt Zouma before drilling the ball into the bottom corner.
Chelsea, who have now lost back-to-back games, remain fifth on 22 points from 13 games, three behind leaders Tottenham Hotspur and Liverpool who meet at Anfield on Wednesday.
"At 1-0 we should see the game out," said Lampard who suggested his team may have become complacent after their 17-match unbeaten run before defeat at Everton last week.
"If you are not playing that well, which we weren't at that time, hang on to 1-0, don't allow counter-attacks," he said.
"Performance is what gives you results. We were playing very well, a long unbeaten run and then maybe the lads think we are playing well and the minute you think you are playing well things like this can happen," he added.
Wolves, who had lost their last two matches, move up to ninth place on 20 points.
(Reporting by Simon Evans; Editing by Ken Ferris)
