The Spaniard rose the highest to meet a corner and thumped home an unstoppable header from almost point-blank range.
The Reds were riding on Sadio Mane's first-half strike until that point, as some goof-up inside the penalty box allowed the Senegalese to slot into an empty net.
It was proving to be enough for the holders to secure all three points, despite a bog standard performance, but were caught out from a set-piece once again.
The draw ends Liverpool's three-match winning streak but, more importantly, seriously jeopardizes their Champions League ambitions - West Ham remain two points ahead of them while fifth-placed Chelsea have a game in hand over them.
Here are the player ratings for Liverpool:
Alisson - 7/10
The big man made some big saves in the game which kept the Reds in the match until the end, including one crucial stop to deny Tyler Roberts from scoring a huge chance in the 77th minute. It went well until Llorente equalized with a close-ranger header.
Trent Alexander-Arnold - 7/10
Another good performance from Alexander-Arnold as we got to see shades of his former self, even assisting Mane for the opener following some brilliant work down his flank.
Fabinho - 6/10
The Brazilian lacked his usual composure and misplaced several passes too. He almost gifted Leeds a goal in the first-half with a loose pass, but managed to recover in time to make the challenge.
Ozan Kabak - 6/10
A good first-half performance from the January arrival, keeping Patrick Bamford in check with his close markings. But after the break, he lost some of that robustness, and was also beaten by Llorente for the goal.
Andrew Robertson - 7/10
The Scotsman made up for his lack of attacking flair with a solid shift in defense, making a game-high of seven clearances.
Thiago Alcantara - 7/10
Of all their midfielders tonight, Alcantara shone the brightest. He combined brilliantly with the players around him and hooked up crosses for Salah and Alexander-Arnold to feed on, whilst also laying three key passes, the most by a Liverpool player.
Georginio Wijnaldum - 6/10
The Dutchman held his ground well for much of the game but looked wobbly when Leeds upped the ante in the second-half, with Roberts even taking the mickey out of him with some quick feet at one point.
James Milner - 6/10
Besides an overlapping run or two and a wayward attempt at goal, there was nothing much to write home about Milner.
Diogo Jota - 6/10
The striker was not at his piercing best tonight. He fired one good chance far and wide in the first-half, and was snuffed out of some other opportunities at the last second.
Roberto Firmino - 6/10
He looked sharp in the build-up play during the opening exchanges and even helped out defensively as the match wore on, but Firmino couldn't really stamp his authority on the match.
Sadio Mane - 7/10
A lively performance from the embattled Senegalese, who also finally ended his goal-drought of 10 games with a simple finish. He drifted off slightly after the break.
Alex Oxlade-Chamberlain - 5/10
He had a chance to win it at the death but failed to get his shot away properly as Illan Meslier made a comfortable save.
Mohamed Salah - 6/10
The prolific Egyptian always looked to get in behind the Leeds defense but scuffed one shot away and saw the other one blocked.