Match ends, Wolverhampton Wanderers 2, Chelsea 1.
Wolves boss Nuno Espirito Santo challenged his side to "maintain these standards" after they fought back from a goal down to stun Chelsea and gain their first victory in seven Premier League matches.
Two goals in four second-half minutes - from Raul Jimenez and Diogo Jota - gave the hosts victory after Ruben Loftus-Cheek's 25-yard effort was headed into his own net by Wolves captain Conor Coady after only 18 minutes.
"This doesn't mean all the problems are solved," said Nuno, whose side won for the first time since their 1-0 away victory at Crystal Palace on 6 October.
"It was a very good performance. In the first half, the organisation and staying in the game was important.
"In the second half, we showed desire to go in front. It was fantastic work from the boys. The only way to play these teams is you have to run more than them and when you have your chances take them. We have to maintain these standards."
Wolves' win leaves them 12th in the Premier League, only four points behind sixth-placed Everton.
Chelsea had 70% possession and 17 attempts but suffered back-to-back away league defeats despite dominating the first half.
"Of course I'm disappointed," said Blues boss Maurizio Sarri. "We played very well in the first half and could have killed the game.
"Suddenly we conceded a goal and we were not the same team. It's very difficult for me to understand why - I can't understand the reaction.
"We played very well for 55 minutes and then suddenly we were another team."
After Chelsea's goal, they had chances to extend their lead but Willian had a free-kick tipped over, Antonio Rudiger shot off target and N'Golo Kante fired just wide.
Those misses proved costly as Jimenez's low strike, following a fine run from 18-year-old midfielder Morgan Gibbs-White, made it level.
Wolves scored what proved to be the winner four minutes later as Matt Doherty's cross was finished at the back post by Jota for his first Premier League goal.
Sarri's side drop down to fourth below Tottenham and remain 10 points behind leaders Manchester City, who they play at Stamford Bridge on Saturday.
Wolves end 'bad moment' in style
Wolves were promoted to the Premier League after winning the Championship last season and picked up 15 points from their opening eight top-flight matches, but had then gained only one point from their next six.
The Portuguese boss admitted his side were "in a bad moment" after losing 2-1 at Cardiff on Friday and looked on course for another defeat when the visitors went ahead after only 18 minutes and had opportunities to extend that lead further.
Wolves had been restricted to two headers off target from Jimenez in the first half, but the Mexican scored his fourth league goal of the season in the 59th minute to start the fightback.
Gibbs-White, who was part of the England team that won the Under-17 World Cup in 2017, was making his first Premier League start in place of the suspended Ruben Neves and did superbly to run at the Chelsea defence and release Jimenez.
The striker shot low at goal and the ball went under Blues goalkeeper Kepa Arrizabalaga as the hosts scored with their first shot on target.
They also found the net with their second attempt on target four minutes later.
Willian thought he had been fouled by Joao Moutinho but Jonathan Moss waved play on and that enabled Moutinho to set up Doherty who had enough space to cross from the right for Jota's winning goal.
Another defeat on the road for Chelsea
This was Chelsea's first away match since their 3-1 loss at Tottenham and Sarri will be wondering how they were beaten again.
The Italian handed first league starts of the season to defender Andreas Christensen and midfielders Cesc Fabregas and Loftus-Cheek, who had scored when he came off the bench in the 2-0 win over Fulham on Sunday.
The England midfielder will try to claim the 18th-minute goal when he shot from 25 yards out, although it could go down as an own goal as Coady, trying to block the effort, stooped low to head it, but could only steer it past Rui Patricio.
Chelsea's lead looked a comfortable one as Willian's 22-yard free-kick was excellently tipped over by Patricio and Rudiger wastefully shot over.
And the Blues may feel they should have had a penalty early in the second half when Loftus-Cheek's low cross was destined to present Alvaro Morata with a simple tap in, only for the Spaniard to fall under Willy Boly's challenge.
Referee Moss, however, waved away Chelsea's penalty appeal.
Wolves' Moutinho was also fortunate to not see a second yellow card for a foul on Loftus-Cheek, which came only two minutes after he had been cautioned for fouling Hazard.
But still Chelsea created chances as Willian shot over and Kante fired inches wide in the 57th minute before two goals in four minutes turned the match around.
For Morata, preferred up front ahead of Olivier Giroud, it was another unconvincing performance with him wasting his only chance - shooting over from 25 yards after only 11 minutes.
Giroud replaced Morata in the second half but he too headed over from a corner, Hazard shot just off target and Fabregas missed with a curling effort as Wolves held on.
Rare Wolves win on a Wednesday - the stats
- Wolves have won a top-flight game played on a Wednesday for the first time since beating Chelsea 1-0 at Molineux in January 2011.
- Wolves have defeated 'Big Six' opposition in the Premier League for the first time since February 2011 against Manchester United (2-1) - they were winless in their previous 18 such games.
- Chelsea have lost consecutive away games against newly-promoted sides for the first time since December 1999 (versus Watford and Sunderland).
- Each of Wolves' last nine league goals at Molineux have been scored in the second half.
- Wolves' Morgan Gibbs-White (18 years and 312 days) became the youngest player to assist a Premier League goal against Chelsea since Francis Jeffers for Everton in November 1999 (18 years and 298 days).
- Chelsea's Ruben Loftus-Cheek has scored three goals in his last three Premier League games, as many as in his previous 48 combined in the competition.
- Raul Jimenez has been directly involved in 53% of Wolves' goals in the Premier League this season (eight of 15).
- Diogo Jota ended a run of 15 league games without a goal for Wolves, last netting against Bolton in the Championship in April.
Man of the match - Ruben Loftus-Cheek (Chelsea)
'What I've dreamed of' - what they said
Wolves teenager Morgan Gibbs-White, who assisted a goal on his first Premier League start: "It's what I've dreamed of as a kid, growing up wanting to play in the Premier League. To get three points is a massive boost.
"We had to [defend well] with the quality they have. We have a determination and want to win. But we need to show that in all our games, not just against the big teams."
Chelsea midfielder Ruben Loftus-Cheek: "We felt in control in the first half. We felt comfortable and were playing good football. They came out fast in the second half and we were sloppy as a team. If you're sloppy you pay for it in the Premier League.
"We should expect to play well whoever plays. We need to turn this around quickly because we have a tough game at the weekend [Manchester City]. We're very disappointed. We pick our heads up and go again."
Chelsea entertain Premier League leaders Manchester City at Stamford Bridge on Saturday (17:30 GMT), before Wolves play at Newcastle on Sunday (16:00 GMT).
- 11Rui Patrício
- 16CoadyBooked at 61mins
- 28João MoutinhoBooked at 54mins
- 27SaïssBooked at 37mins
- 29VinagreBooked at 68mins
- 9JiménezSubstituted forDendonckerat 81'minutes
- 18JotaSubstituted forCavaleiroat 88'minutes
- 17Gibbs-WhiteSubstituted forHélder Costaat 72'minutes
- 10Hélder Costa
- 27ChristensenBooked at 90mins
- 3AlonsoBooked at 90mins
- 7KantéSubstituted forKovacicat 77'minutes
- 4FàbregasBooked at 64mins
- 22WillianSubstituted forPedroat 65'minutes
- 29MorataSubstituted forGiroudat 65'minutesBooked at 86mins
- 10E Hazard
- 30David Luiz
- Jonathan Moss
- Shots on Target
Second Half ends, Wolverhampton Wanderers 2, Chelsea 1.
Andreas Christensen (Chelsea) is shown the yellow card for a bad foul.
Foul by Andreas Christensen (Chelsea).
Hélder Costa (Wolverhampton Wanderers) wins a free kick on the right wing.
Offside, Wolverhampton Wanderers. Rúben Vinagre tries a through ball, but Ivan Cavaleiro is caught offside.
Marcos Alonso (Chelsea) is shown the yellow card.
Foul by Marcos Alonso (Chelsea).
Matt Doherty (Wolverhampton Wanderers) wins a free kick on the right wing.
Substitution, Wolverhampton Wanderers. Ivan Cavaleiro replaces Diogo Jota.
Attempt missed. Cesc Fàbregas (Chelsea) right footed shot from the centre of the box is too high.
Olivier Giroud (Chelsea) is shown the yellow card.
Foul by Mateo Kovacic (Chelsea).
Willy Boly (Wolverhampton Wanderers) wins a free kick in the defensive half.
Attempt missed. Olivier Giroud (Chelsea) with an attempt from the centre of the box is too high. Assisted by Eden Hazard with a cross following a corner.
Corner, Chelsea. Conceded by Rúben Vinagre.
Foul by Ruben Loftus-Cheek (Chelsea).
Leander Dendoncker (Wolverhampton Wanderers) wins a free kick in the defensive half.
Substitution, Wolverhampton Wanderers. Leander Dendoncker replaces Raúl Jiménez.
Attempt blocked. Olivier Giroud (Chelsea) left footed shot from outside the box is blocked. Assisted by Eden Hazard.