Mount and Tuchel react after Chelsea's 3-2 loss to West Ham.

Arthur Masuaku scored a bizarre late winner as West Ham twice came from behind to beat Premier League leaders Chelsea at London Stadium.

Arthur Masuaku scored a bizarre late winner that sent the Hammers supporters into ecstasy. [GETTY]

Chelsea boss Tuchel blamed individual mistakes after they lost their first game of the season on Saturday afternoon as they were beaten 3-2 by David Moyes’ West Ham.

West Ham came from behind twice to secure a 3-2 win over Premier League table-toppers Chelsea.

The East London club became the first side to score more than one goal against the European champions on Saturday afternoon.

Brazil defender Thiago Silva broke the deadlock for the Blues in the 29th minute, heading Mason Mount's corner past keeper Lukasz Fabianski.

Then the homeside responded when they were gifted a chance by Chelsea keeper Edouard Mendy, who brought down Jarrod Bowen following a poor backpass from Jorginho, and Manuel Lanzini stepped up to score the leveller from the penalty spot.

Four minutes later, Thomas Tuchel’s side took the lead again via Mason Mount as the England midfielder smashed Hakim Ziyech’s perfect cross to make it 2-1 just before half-time.

Centre-back Thiago Silva broke the deadlock at the London stadium [GETTY]

In the second half, the Hammers hustled hard and eventually got their reward through Bowen, whose low drive from the edge of the area made it 2-2 before Arthur Masuaku scored a bizarre late winner that ensured West Ham sealed all three points at the London stadium.

The win strengthens West Ham's place in the top four, while Chelsea will drop to third to if Manchester City and Liverpool win later today.

'Mount: Tired minds, tired bodies.'

Chelsea goalscorer Mason Mount told BBC’s Match of the Day: "We have had a difficult week and the game midweek we came away with three points where maybe we shouldn't have. We made mistakes, the same today. We are making mistakes we haven't done for a while and need to bounce back now. "A lot of games, it can take a toll, but that's not an excuse we can use - we come out here and want to win, it's a derby. We don't concede many, so that is something we need to look at. "It is mistakes we haven't made, tired minds, tired bodies, but we need to keep the standard high. We regroup and come back next game." Asked about what he thought about his goal, the 22-year-old replied: "It felt a nice one, but it doesn't mean much really. It travelled a long way so when it's in the air you have tie to make a decision, I instinctively hit it first time." On Chelsea's Champions League away clash against Zenit in midweek, he said: "We are through but we want to finish top, so we want to win the game, we are going away from home, very cold, we have to be ready for that."

'Tuchel - We had too many mistakes.'

Chelsea boss Thomas Tuchel, who was clearly disappointed with how his side conceded more goals today than any other match in this campaign, told BT Sport: "I don't think we did a bad match, it was OK, we can win with this performance. "It is tough to play here, we did too many individual mistakes, we did already against Manchester United and Watford and got punished - if you want a result at this level you have to minimise mistakes. We talked about it before, it's obviously not helped." On the penalty his side conceded, the German said: "Everybody is involved, the pass is not the best decision, the orientation is not the best, we can save it but the decision-making is also not the best from Edu in this moment.

"We created a lot of half-chances, a lot of touches in the box, but sometimes you need a bit of luck, a deflected shot or loose ball that falls to our feet. Their third one is a strange one, the two big chances they had in the first half were our mistakes. "We could not finish it with clear and better chances, be more ruthless, we struggled also in defending some situations. "Every loss is a bump in the road, that will not hold us back from what we demand from us but we need to play more accurate, more stable and reduce big mistakes."

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