A defensive error from Jamie Carragher had allowed Nikica Jelavic to put Everton ahead in the first half, but Sylvian Distin allowed Luis Suarez through with a short back-pass to level the scores just after the interval.
The stage was then set for Andy Carroll - who had missed several glorious chances earlier in the contest - to finally find the back of the net three minutes from time from a set-piece to send Liverpool to their second domestic cup final of the season.
They will head back to Wembley in three weeks' time to meet the winner of Sunday's last-four encounter, another local derby between Londoners Chelsea and Tottenham.
After both clubs observed a minute’s silence for the anniversary of the Hillsborough tragedy this weekend, decibel levels soared during the opening stages for every promising pass and surge into the opposition’s final third.
However, outside of Leighton Baines’ overhit free-kick in the sixth minute and Stewart Downing’s scuffed effort after cutting inside from the left moments later, the contest began as a rather cautious and balanced affair.
Everton began to slowly edge several battles for possession, territory and confidence as hesitation amidst the Reds’ back line became apparent, something skipper Phil Neville exploited on 20 minutes with a mazy run on the right before his deflected assist teed up a Jelavic overhead kick attempt, caught by Brad Jones in goal.
But four minutes later the goalkeeper, in the starting line-up courtesy of suspensions for Pepe Reina and Doni, was left helpless by his defenders as the Toffees took the lead.
Carragher and Daniel Agger, deputising at left-back, took an eternity deciding which of them would clear a loose ball inside their penalty area, and the Englishman’s eventual attempt was closed down by Tim Cahill and deflected into the path of Jelavic to stroke home the opener.
Kenny Dalglish’s side failed to convince for the most part in their initial chasing of the game, but came out for the second half more determined and energised, and almost pegged their neighbours back within two minutes of the restart.
After the Everton defence had dealt with a number of balls into the danger zone, a fantastic delivery from Downing met the head of Carroll at the far post, only for the record signing to inexplicably nod it down and wide of the upright with the goal at his mercy.
Fifteen minutes later David Moyes’ men would gift Liverpool another big chance to score, and this time they took it.
Suarez did superbly well in hounding Distin into a dead end before reading his attempt at a back pass to Tim Howard and sprinting into a one-on-one, from which he slipped the leveller beyond the American keeper.
Both teams continued to push and Carroll sent a serious chance low and wide of the far post with 12 minutes to go, shortly before Jelavic also missed the target from Marouane Fellaini’s headed flick-on. Carroll then had another effort blocked by his own team-mate, substitute Maxi Rodriguez.
But the much-maligned forward would have the last laugh as Seamus Coleman, on for Magaye Gueye, somehow escaped a second booking for a trip on Steven Gerrard in the closing stages.
Another replacement player, Craig Bellamy, sent in the free-kick which Carroll rose well to meet, connecting with enough of a blind header to put his side ahead for the first time in the match.
The Reds had their tails up for the finale and had little defending of a dramatic equaliser to do, even coming within inches of doubling their advantage when Maxi hammered a Suarez centre against the far post.
But 2-1 was enough in the end for Dalglish and his men, who will return to the national stadium with hopes of completing a cup double to compensate for their disappointing league campaign.