Jurgen Klopp bemoaned numerous refereeing decisions as Liverpool saw their 20-game unbeaten run in the Premier League ended by West Ham.

Alisson, under pressure from Angelo Ogbonna, punched into his own net to gift the lead to David Moyes' men, who were previously winless in 10 top-flight attempts against the Reds.

Liverpool protested their goalkeeper was fouled from Pablo Fornals' inswinging corner, and Klopp's side were further infuriated when Aaron Cresswell appeared to lunge high into a sliding tackle on Jordan Henderson.

However, referee Craig Pawson and VAR official Stuart Attwell did not see reason to punish the left-back before Trent-Alexander Arnold equalised four minutes before the break.

Fornals nudged Moyes' side back into the lead and Kurt Zouma all but clinched the win as Liverpool conceded two goals from corners in the same Premier League game for the first time since August 2017.

Divock Origi brought the scoreline back to 3-2, but Liverpool could not find an equaliser and, after the game, Klopp's focus was on the officiating as he once again questioned the thought processes behind some of the decisions he felt cost his side.

"Key moments cost us today, the goals and some situations have to go another way," Klopp told Sky Sports post-match.

"Let's talk about the game. The first they score is a foul on the goalkeeper; the arm goes into Alisson's arm, so how can he catch it? That makes no sense.

"What can Alisson do? That is why the goalie is protected. If a player goes up in the air with his arm, it is an important part of the body for the goalkeeper.

"Aaron Cresswell's was a reckless challenge on Jordan Henderson, even when he touched the ball before, so you have to control your body.

"[These were] two situations which were influential, but West Ham did not make the decisions, and they won the game.

"People will say I am making excuses, but I am calm. You need normal decisions from a referee, and he did not do that."

In all competitions, this was Liverpool's first defeat in 26 games, ending their joint-longest unbeaten run since they joined the Football League in 1893.

And Klopp acknowledged his side can improve in their next game against Arsenal after the international break.

"We lost too many balls, that is why they had counter-attacks," he continued. "At 1-1, we had them where we wanted. It looked like we lost a bit of patience, we had a lot of situations where we got to the touchline but could not make it count.

"They dropped really deep, so it does not make it easy, you have to force and fight them down in the final third. Little things decided it and a few things went against us.

"We were not that calm in the decisive moments, they could not get us. When you try to put the ball into the box they had eight, nine players, so we have to go again, do it again. We were not patient enough.

"We can be better, 100 per cent. You cannot always play your best result, you have to grind out a result, but they scored three goals and we didn't."