Villarreal players celebrate the winner against Liverpool in their Europa League semifinals, April 28, 2016.Reuters

Liverpool had put in a solid away European performance for 91 minutes, before a loss of possession and a slip in concentration gave Villarreal the goal and advantage they craved in this Europa League semifinal. Just when it looked like the first leg at the El Madrigal would end 0-0, Adrian Lopez popped up in the right place at the right time to give the home team a 1-0 victory.

Having negotiated Borussia Dortmund in the most dramatic of circumstances in the quarterfinals, Liverpool might have been expected to put on another impressive European show, but for large parts of this game, it was about staying smart and making sure the tie was very much alive and in their hands going into the second leg at Anfield.

That plan was working well as the midfield of Joe Allen, Lucas and James Milner played quite well, keeping the Villarreal attacks to a minimum, with the back four, when the Spanish side did penetrate through, doing what they needed to as well.

However, right at the end, Liverpool, in a bid to find the winner, lost their shape. Adam Lallana lost possession, and just like that the ball reached Liverpool's half, via the excellent Bruno Soriano. Denis Suarez then found a pass across the box for Adrian Lopez to slot home and give Villarreal a vital win.

"I am pleased with the performance, a lot of parts we did really well," Liverpool manager Jurgen Klopp was quoted as saying by The Guardian. "Villarreal are a good side but Liverpool are a good side, too. To control a game like this in most parts of the game is good. To concede from a 92nd-minute counterattack, it sounds like it is -- not too good. Everyone knows it and it should not happen."

Klopp felt the exuberance of youth told in the end, but the manager is also of the belief that the second leg at Anfield will be a completely different affair, a match in which Liverpool need to, and will, attack a lot more.

"Maybe the youth came through at that point," Klopp, who decided to start with Roberto Firmino up front rather than Daniel Sturridge for this match, added. "Until then it was really a professional performance. To be honest it is the first leg. My first thought as everyone around me was celebrating was: 'Sorry, but it is not over, you have to come to Anfield too and we will be ready.'"