Match ends, Arsenal 0, Liverpool 2.
Liverpool reached their first Wembley final for six years as a double from "world-class striker" Diogo Jota set up a Wembley date with Chelsea in the Carabao Cup.
Jota brilliantly filled the gaps left by Mohamed Salah and Sadio Mane - away at the Africa Cup of Nations - as his lethal finishing wrecked Arsenal's trophy hopes for this season after a goalless semi-final first leg at Anfield.
Arsenal started impressively, Alexandre Lacazette hitting the woodwork from a free-kick, but Liverpool struck after 19 minutes when Jota's scuffed shot after a fine run beat scrambling Arsenal keeper Aaron Ramsdale.
Lacazette missed Arsenal's best chance after the break, shooting over when clean through, but Liverpool had chances of their own and sealed their first final in this competition since the 2016 loss to Manchester City when Jota ran on to Trent Alexander-Arnold's pass and lofted a precise finish over Ramsdale with 13 minutes left, the goal given by VAR after initially being disallowed for offside.
Reds boss Jurgen Klopp said: "We scored two wonderful goals - Diogo Jota was on fire. We were completely convinced when he arrived at the club he would help us massively.
"Since he is here he has made another step, he has turned into a really world-class striker."
Arsenal's misery was complete when Thomas Partey, on as a substitute after returning from Afcon at midday, received a second yellow card for a senseless late challenge on Fabinho.
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Jota fills the breach
The absence of Salah and Mane was bemoaned when Liverpool drew a blank against Arsenal's defiant 10 men in the semi-final first leg at Anfield - but there were no such complaints here, with Jota the match-winner.
When he arrived from Wolverhampton Wanderers in a £45m deal before the start of last season, the Portuguese was seen as the safety net behind the big three of Roberto Firmino, Mane and Salah.
Instead, he has proved a wonderfully consistent addition when measured by goals and performances, and this was a superb individual display that more than compensated for the absence of the Reds' world-class duo.
He has scored 27 goals in 57 games for the club, including 14 in all competitions this season.
Klopp said: "Mentality mixed with quality is the reason we signed him. Of course he scored two goals, he is incredibly important to us, so it is that mix of his skills that is really exciting. He is in good shape as well, and long may it continue."
Jota's first goal carried a little good fortune as the shot was half-hit, but the driving run that set it up was a sign of his threat.
The second was a masterpiece of clinical composure, lifting the ball over Ramsdale, with VAR confirming that the timing of his run on to Alexander-Arnold's pass was perfection.
Liverpool manager Klopp was elated at the final whistle, with his various mix and match selections throughout this competition having resulted in a big Wembley meeting with Chelsea.
Mane and Salah will be back for that in late February - but how can he even contemplate leaving Jota out after this?
Klopp added: "The mood in the dressing room is over the moon. The boys were exceptional. First half, Arsenal started lively, then we calmed it down and played good football."
Arsenal miss big chance
The banks of empty seats at Emirates Stadium told the story of the bitter disappointment of the Arsenal fans as their night of big expectation fizzled out.
The Gunners started at a high tempo but struggled to regain their rhythm after Jota's early strike and now a place in the top four in the Premier League is their only aim this season.
There is lots of youthful promise in this Arsenal side, but the shock FA Cup loss at Championship side Nottingham Forest and now this defeat will be a deflating experience.
The cancellation of the first leg meant Arsenal had the psychological advantage of the second leg at home, and hopes were high after a brilliant backs-to-the-wall performance at Anfield.
Instead, they lost their way and Arsenal's big chance came and went when Lacazette's poor finish when clean through wasted their opportunity for an equaliser.
Liverpool pounced and Arsenal once more showed that strain of indiscipline when Partey, with the game over, lunged into a nonsensical challenge on Fabinho to bring their night to a thoroughly abject conclusion.
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- Shots on Target
Second Half ends, Arsenal 0, Liverpool 2.
Takumi Minamino (Liverpool) is shown the yellow card for a bad foul.
Foul by Takumi Minamino (Liverpool).
Kieran Tierney (Arsenal) wins a free kick in the defensive half.
Foul by Ibrahima Konaté (Liverpool).
Eddie Nketiah (Arsenal) wins a free kick in the defensive half.
Second yellow card to Thomas Partey (Arsenal) for a bad foul.
Fabinho (Liverpool) wins a free kick in the defensive half.
Foul by Thomas Partey (Arsenal).
Attempt saved. Andrew Robertson (Liverpool) left footed shot from the left side of the box is saved in the centre of the goal. Assisted by Curtis Jones.
Takumi Minamino (Liverpool) wins a free kick in the defensive half.
Foul by Gabriel Magalhães (Arsenal).
Thomas Partey (Arsenal) is shown the yellow card for a bad foul.
Neco Williams (Liverpool) wins a free kick in the attacking half.
Foul by Thomas Partey (Arsenal).
Substitution, Liverpool. Neco Williams replaces Roberto Firmino.
Attempt missed. Curtis Jones (Liverpool) right footed shot from outside the box misses to the left. Assisted by James Milner.
Curtis Jones (Liverpool) is shown the yellow card for a bad foul.
Foul by Curtis Jones (Liverpool).