Liverpool survived a huge scare before beating Villarreal 3-2 and advancing to their third Champions League final in five seasons.
Villarreal looked on their way to another stunning upset after opening a two-goal lead in the first half to cancel their 2-0 first-leg defeat, but the Spanish club wilted and Liverpool came from behind to go through 5-2 on aggregate in a thrilling contest.
The victory means they will contest the Champions League final on May 28 against Manchester City or Real Madrid, and can still win four trophies after already lifting the League Cup, and face Chelsea in the FA Cup final on May 14 and trail City by a point in the Premier League.
After Boulaye Dia and Francis Coquelin put Villarreal in command before half-time Fabinho, substitute Luis Diaz and Sadio Mane scored in the second half to propel Liverpool into the final for the first time since winning their sixth European title in 2019.
"Difficult, really difficult. We came here and they played very well first-half," defender Trent Alexander-Arnold told BT Sport. "We regrouped at half-time and got the game by the scruff of the neck. We did what we needed to do.
"We expected it but sometimes you can't control the game how you want to. They scored early doors, which is what they wanted to do. But we got it done."
Fabinho added: "They gave it everything in the first half. We knew the first 15 minutes would be really important. They scored early and it gave them confidence and the fans felt it.
"It was a hard first half for us, maybe the hardest of the season. But you have to be ready for everything and try to play football. After our first goal we controlled the game. That is it and we are in the final."
Liverpool were aided and abetted by a distinctly ordinary goalkeeping performance from the hosts’ Geronimo Rulli.
The Argentinian had a hand – or lack of one – in all of Liverpool’s three goals in 12 second-half minutes and was culpable for at least two.
Villarreal’s misery was completed when Etienne Capoue was sent off for a second yellow card for a foul on Curtis Jones late on.
Thunderstorms on Monday night had given way to persistent rain throughout matchday – causing some localised flooding – and while that may have dampened the surface inside Estadio de la Ceramica it did not affect the atmosphere.
Manager Jurgen Klopp had warned his side would have to suffer in parts of this tie but he could not have expected that to start so early and last for so long.
The La Liga side, conquerors of Juventus and Bayern Munich, did not manage a shot on target at Anfield last week but scored with their first in only the third minute.
Pervis Estupinan’s cross was met at the far post by Capoue, whose mis-hit shot found Dia to score into an unguarded net.
Boosted by the return of striker Gerard Moreno, Villarreal were aggressive and direct but the manner in which the visitors failed to handle that was startling.
Liverpool were overrun in midfield and their failure to string any significant sequence of passes together only contributed to the chaotic nature of their performance.
The second goal came four minutes from the interval when Capoue’s inviting cross to the far post was met by Coquelin, who outjumped Trent Alexander-Arnold to float a header into the top corner.
Swapping Diaz for Diogo Jota for the second half sparked an immediate improvement for Liverpool, allowing Mane to play centrally.
It finally told in the 62nd minute when Salah slid in Fabinho and his low, angled drive went through Rulli at his near post.
The two-goal cushion from the first leg was restored five minutes later when Diaz’s downward header from a left-footed Alexander-Arnold cross was only half-saved and Liverpool’s tumbling Colombia international inadvertently turned it in.
Rulli’s eventful night was not over and when he charged 20 yards outside his area to meet the onrushing Mane, the Senegal international sidestepped him before rolling the ball into an open goal.
Klopp said he would be watching the return leg of City’s semi-final against Real.
He told BT Sport: “Yes I will watch it, of course. Whoever it will be, it will be massive.
“Not that I would wish for one or the other, but it will be massive and whoever wins tomorrow night or gets the result will deserve it and we will face each other in Paris.”