Goals from Fabinho, Luis Diaz and Sadio Mane saw the Reds recover from a 2-0 half-time deficit in Tuesday’s semi-final second leg at Estadio de la Ceramica and progress 5-2 on aggregate.
Villarreal cancelled out Jürgen Klopp’s side’s first-leg advantage courtesy of Boulaye Dia’s early strike and Francis Coquelin’s header, but the visitors emerged for the second period a different team, with half-time substitute Diaz in inspired form.
The Reds will now face either Real Madrid or Manchester City in Paris in the third Champions League final of Klopp’s glorious reign.
Team news
Klopp made five changes to his starting line-up as Trent Alexander-Arnold, Ibrahima Konate, Thiago Alcantara, Fabinho and Mohamed Salah returned.
The players to make way - Joe Gomez, Joel Matip, Jordan Henderson, James Milner and Diaz - were all named on the bench.
First half
The raucous atmosphere inside the stadium was ratcheted up further when the hosts made a dream start through Dia, who was on hand to convert Etienne Capoue’s unselfish lay-off from a cross into the area.
Roared on, Villarreal looked to capitalise further on their early ascendancy and Andy Robertson was required to make a block to repel Gerard Moreno’s back-post header.
Liverpool navigated their way through a testing spell without sustaining any more damage, though, and offered a warning of their threat when Salah outmuscled Pervis Estupian and found Diogo Jota, only for the No.20’s touch to let him down as he bore down on goal.
Vociferous Villarreal appeals for a penalty - after Alisson Becker dived at the feet of Giovani Lo Celso as the Argentinian tried to round him - were waved away, but Emery’s team would wipe out the Reds’ aggregate lead four minutes before the break.
Capoue crossed from the byline and Coquelin climbed above Alexander-Arnold at the back post to direct his header into the top corner and prompt another explosion of noise from the jubilant home fans.
Second half
Liverpool’s level of performance was markedly improved Immediately after the restart with half-time substitute Diaz, stationed on the left, a constant menace.
A trademark cross-field pass by Alexander-Arnold located the Colombian and, once the ball had been worked back to the right-back, he produced a fine cross that Geronimo Rulli unconvincingly punched away.
Alexander-Arnold then saw a deflected shot loop onto the top of the crossbar before Diaz miscalculated a bicycle kick.
It felt like a matter of time until a Reds goal arrived and so it proved, as a patient, probing sequence of passing concluded with Salah’s pass inviting Fabinho to shoot or cross from a tight angle.
He chose the former and his low drive squirmed through Rulli to restore Liverpool’s aggregate lead.
Diaz saw a shot deflect off the outside of the post but the No.23 was not to be denied the goal his display merited as he nodded Alexander-Arnold’s left-footed delivery in to provide a cushion for the visitors.
There was only one team in it now and the comeback was completed with 16 minutes remaining.
The relentless Mane poked the ball past the onrushing Rulli and then kept his cool to calmly slot home the Reds’ third of the evening and rubber-stamp their progress.
With the tie won, Klopp rang the changes from the bench and Villarreal discipline began to waver, as Pau Torres was booked for scything Mane down before Capoue was sent off for a second yellow card.
Salah could have crowned the evening with another goal, but the No.11 shot wide after being fed by Mane. However, the job was done and another Champions League final beckons.