Chelsea's hopes of qualifying for next season's Champions League took another huge blow as they suffered a 1-0 defeat at home to Manchester United.
Matheus Cunha's goal on the stroke of half-time proved to be enough for Michael Carrick's side to solidify third place in the Premier League and leave Liam Rosenior's men further adrift of a return to Europe's elite competition.
Hundreds of Chelsea supporters protested against the clubs owners BlueCo prior to the game as they called for an end to the regime. And those inside the stadium voiced their dissatisfaction come the final whistle with boos that could be heard all around west London.
Chelsea dominated throughout the first-half, and can only be furious at themselves to not have been ahead at the break.
Willian Estevao clipped the outside of the post with a curling effort inside the first quarter of an hour, while the returning Enzo Fernandez spurned an even better opportunity as he shot wide from just outside the six-yard-box.
Up until their opener, United had managed an xG of just 0.03. However, with Wesley Fofana off the pitch after picking up a knock, they capitalised as Bruno Fernandes secured his 18th Premier League assist of the season by finding Cunha whose first time strike nestled into the top corner.
The Blues continued to look the more likely to score in the second period, with Liam Delap seeing his header cannon back off the crossbar just before the hour mark. A near identical chance then fell to Fofana, but he found the exact same result.
By hook or by crook, the unorthodox Manchester United back four that saw stellar performances from Ayden Heaven and Noussair Mazraoui at centre-back held on for a rare clean sheet to take all three points.
The home supporters loudly booed their team at the final whistle, both in disappointment of their lack of finishing touch and the fact they now find themselves 10 points behind United in the Premier League table.
They also remain four points behind fifth-placed Liverpool, having played a game more as their Champions League hopes slowly slip away.
Chelsea boss Liam Rosenior speaking with TNT Sports:
"Up until the box, we were very good. I can only say what I saw, I thought we were the dominant team from minute one until the end of the game.
"But to lose this game in the manner we did is extremely disappointing because we had many opportunities to win it.
"It's been a difficult spell. We're making key errors in key moments and we're not taking advantage of the chances we're creating.
"When you do that and you don't win games of football, it has to turnaround quickly.
"I'm delighted we have a game on Tuesday to get this out of our system and we have to go to Brighton and put things right.
"We created many chances today. It's not about the creation of the chances, but the taking of them.
"We hit the woodwork four times, so we're not far away."
On Champions League race:
"We just need to win the next game. We can't think about other teams, we have to focus on ourselves and we have to make sure we put things right."
Man Utd boss Michael Carrick speaking with TNT Sports:
"It was massive for us, a big win. To come here and keep a clean sheet like we did, and defend the way we did, I thought it was a magnificent performance.
"We don't want to look behind us, we want to keep improving and move forward. We're still not high enough, we want to be higher, but it was a big win and something the supporters can enjoy.
"It was a disappointment against Leeds, but to come here and respond like that, especially in a tough place, was really pleasing. Some games are about getting the result, and there's no shame in that.
On selecting his defence:
"There was a lot of work in the last couple of days preparing the team, especially with the new back four. Ayden [Heaven] and Nous [Mazraoui] coming in were incredible. At such a young age, Ayden isn't really playing centre-back in a back four, so a lot of credit goes to the coaching staff and the players for taking that on board."
Analysis from Your Site' Joe Shread:
That's six defeats in seven games for Chelsea. That's four defeats in a row in the Premier League - all without scoring.
Three home defeats in a row - the first time since 1993 they've managed that. And it's Chelsea's Champions League hopes in tatters.
Loud boos at full-time. The pressure on Liam Rosenior is red hot.
Analysis from Your Site' Callum Bishop:
Many would've understandably questioned the decision to start Noussair Mazraoui at centre-back this evening. The Moroccan hasn't got much experience in that position, and he was partnering a youngster without much experience full stop in Ayden Heaven.
Pre-match, moving Luke Shaw central seemed to be the most obvious option. Perhaps Manuel Ugarte too after he slotted in during the defeat to Leeds.
Instead, it was Mazraoui. The ultimate utility man. And it paid off too. He looked calm on the ball and didn't get too exploited aerially, even if there were one or two moments.
He has played all across the defence, slotted into the holding midfield role. He's even tried out as a number 10. But of all his makeshift performances, this was by far his best yet.
