Boss Frank Lampard was disappointed his Chelsea players dropped their standards for the second time in four days to suffer a last-gasp Premier League defeat at Wolves.
Pedro Neto struck in the fifth minute of stoppage time to claim a 2-1 comeback win for the hosts.
Olivier Giroud opened the scoring for the visitors four minutes after the break before Daniel Podence’s deflected effort pulled Wolves level.
Kurt Zouma hit the crossbar for Chelsea and the hosts also had a late penalty awarded and then overturned.
Victory would have taken the visitors top of the Premier League but they slipped to back-to-back top-flight defeats for the first time in over a year after Saturday’s 1-0 loss at Everton.
When asked if the two defeats were just a blip, Lampard said: “That’s up to us, isn’t it? We had a long unbeaten run and everyone sang our praises.
“I was the last one to do that it’s my job to stay level headed on both ends so I shouldn’t get too disappointed tonight as much as I didn’t get too elated after Leeds on the back of a really good run.
“But clearly, when we perform like we did today, that’s not game management, that’s not the quality levels that we are striving for.
“I still think there’s a lot of improvement to be done with the group. I wouldn’t say I’m massively surprised because my experience with the Premier League tells me that if you drop your standards, which we have in two games – and particularly away from home – you can lose football matches.
“That’s a big lesson for the players there.”
Lampard admits his Chelsea players are already feeling festive fatigue after their latest loss.
He added: “There could be some fatigue. I hate to say it after a defeat because it feels like an excuse but even in the first 60 minutes when we were the better team, we didn’t have a zip about us.
“We’ve travelled up to Everton, came back and then travelled to Wolves but everyone is in the same boat.
“We have a couple of injuries in areas which means I can’t make too many changes so I understand that side of it.
“We have been given different kinds of games in these last two. Everton made it difficult for us to break them down – we didn’t succeed with that – and Wolves played very much a counter-attacking style.
“The players have to feel that on the pitch because the message was very clear about their counter-attack and individuals who could hurt us and that’s disappointing.”
Zouma’s header a minute before the break – which smacked the bar – was the closest Chelsea came to an opener before Giroud broke the deadlock soon after half-time.
He got to Ben Chilwell’s cross before Willy Boly for his volley to squirm past Rui Patricio and just over the line before the goalkeeper clawed it back.
But Chelsea failed to build on their lead and Wolves levelled after 66 minutes when Podence tricked Chilwell and Reece James before his shot hit James to fly past Edouard Mendy.
The hosts went for the win and thought they had a penalty 10 minutes from time when James appeared to trip Neto but replays showed there was no contact and referee Stuart Attwell reversed his initial call.
But Wolves won it in stoppage time when they hit Chelsea on the break and, after Neto took on Zouma, he drilled low into the corner to close the gap on Tuesday night’s opponents to two points.
“We always mention character when things go well and then we forget when things don’t go so well the character is still there,” said boss Nuno Espirito Santo.
“Football is played until the last minute of the referee’s whistle but the character goes with the belief, commitment and support of each other. The rest is a game and situations can happen.
“When we work so hard like the boys did today we get our rewards. But happiness lasts for one hour and after an hour we are thinking about Burnley and how tough that is.”
Yet victory came at a price with Leander Dendoncker and Boly both suffering injuries.
Nuno added: “Let’s see what’s happening with Leander. At half-time he wasn’t able to proceed.
“Willy had a problem at the end and the doctors will see and we can say what’s really happening.”