Liverpool wore down Villareal 2-0 in a Champions League first leg semifinal on Wednesday to keep its bid for four-season titles alive.

Pervis Estupinan deflected captain Jordan Henderson's cross into his own net in the 53rd minute and Sadio Mane got the second two minutes later to leave the six-time winners well-placed for the return leg in Spain on Tuesday.

Villarreal, who had stunned Juventus and Bayern Munich in the previous rounds, had frustrated Liverpool in the first half before being well beaten as they created no serious scoring opportunity with just one attempt compared to Liverpool's 20.

Jürgen Klopp's Reds have already won the League Cup, are in the FA Cup final against Chelsea and trail Manchester City by one point in a fierce Premier League title duel.

Should it reach the Champions League final on May 28 in Paris, Pep Guardiola's City could also be its opponent thereafter, City beat Real Madrid 4-3 in a thrilling other first-leg semifinals on Tuesday.

"They are a very organized team and we knew they would make it difficult. It was just important that we kept going and believed that we would eventually break them down. We did that with two good goals," Henderson told BT Sport.

But he warned that "the game is still alive and it will be tough in Villarreal." Villarreal defender Pau Torres shared this view, insisting that "there's a lot of football left in this semi-final yet.

"We go home beaten by two goals but we stay confident. Should we score in the first ten minutes next week we are back in the tie," he said.

Mane had two early chances as Liverpool made its presence felt, first not able to properly control a ball headed on by Ibrahima Konate, and then not managing to head on the target completely unmarked off Mohamed Salah's cross from the right.

Villarreal sat deep, giving the hosts little space as Liverpool mainly tried its luck from a distance. Thiago Alcantara came closest in the 42nd minute when his long-range drive crashed against Villarreal's right post.

Fabinho scored five minutes after the restart was disallowed because Virgil van Dijk was offside before heading on the ball.

Liverpool was finally awarded for its efforts three minutes later when Henderson's cross bounced off Estupinan's foot and high over goalkeeper Geronimo Rulli into the far left corner. And Anfield rejoiced again 120 seconds later when Salah picked out Mane, who beat Rulli for 2-0 with a low shot.

Villarreal was now in danger of falling apart against the relentless Reds. Andy Robertson was offside before volleying home and Luis Diaz aimed inches right. Unai Emery's visitors settled down again in the later stages but created no danger upfront and face an uphill battle to reverse matters at home next week.