Liverpool manager Jurgen Klopp warned his side the Premier League title is not won yet after a 44-game run without defeat in the league came to a crashing end as Watford beat the European champions 3-0 on Saturday.

Klopp's men still enjoy a 22-point lead at the top of the table, but their sluggish return from a two-week winter break earlier this month was finally punished.

Ismaila Sarr's quickfire double and Troy Deeney's strike 18 minutes from time ended Liverpool's hopes of romping to a first league title in 30 years with an unbeaten season.

"What the boys did so far is exceptional but it is not over," said Klopp.

"We did not expect the number of games we won. It was never easy and it will never be easy, so now let's carry on."

After single-goal victories over struggling Norwich and West Ham either side of a Champions League defeat at Atletico Madrid, Liverpool were comprehensively beaten at Vicarage Road.

A 55-point gap separated the sides before kick-off, but the out-of-sorts visitors failed to muster even a single effort on goal in the first 45 minutes.

"You break records because you are 100 percent focused on each step you have to do," added Klopp. "For that you have to perform. Tonight we were not good enough."

Watford's bright start threatened to be blown off course when Gerard Deulofeu had to stretchered off with a nasty looking knee injury that seems certain to end his season.

Andy Robertson's driven effort finally forced Ben Foster into a save early in the second half, but just as Liverpool were beginning to build up a head of steam, they were stung by two quick strikes by Sarr.

Firstly, the Senegalese beat Robertson to Abdoulaye Doucoure's low cross to stab home at the near post.

Six minutes later, Sarr had too much pace for a flat-footed Liverpool defence as he raced onto Deeney's through ball and showed fantastic composure to lift the ball over the advancing Alisson Becker.

Sarr also had a big part to play in Watford's third as he pounced on a short passback and had the vision to pick out Deeney, who lofted the ball nonchalantly over Alisson to make it 3-0.

"It's not acceptable we lose 3-0 here," said Liverpool defender Virgil van Dijk. "We want to strike back straight away."

Watford had thrown away a lead in three of their last four Premier League games to fall back into the bottom three.

But they never looked in any danger of doing so again as they moved back out of the relegation zone on goal difference.

"It's such an important win for us. But it is one win," said Watford boss Nigel Pearson.

"It's in our own hands, and we have to deliver that performance week in, week out."

Sarr should even have had a famous hat-trick with his final touch as he curled wide when one-on-one with Alisson.

However, that was the only gloss missing from a glorious night for Watford as Liverpool remain four wins away from the title.