Liverpool 3 Lille OSC 0
The Reds had trailed 1-0 from the first encounter last week but were always likely to outclass their French opposition after drawing level on aggregate just nine minutes into the second leg.
Alberto Aquilani silenced his critics with a man-of-the-match display against Portsmouth on Monday but he was replaced in the starting line-up by Lucas after failing to shake off the effects of an illness.
But the much-maligned Brazil midfielder played a key role in the opening goal as he was sent sprawling in the box by Adil Rami and Steven Gerrard calmly stroked the early spot-kick past goalkeeper Mickael Landreau.
The Reds were buoyed by their early goal and Torres went on a mazy run only to see his near-post shot deflected out for a corner.
Daniel Agger then found the goalkeeper with a glancing header from a Gerrard corner on the half-hour mark.
But Liverpool were given a warning soon after when Eden Hazard - whose goalscoring performance separated the sides in last week's first leg - burst past Agger and Glen Johnson.
He sped into the box but Pepe Reina managed to repel his powerful shot with his head despite knowing little about the whereabouts of the ball.
Lille were building in confidence but half-time took the wind out of their sails and Torres took full advantage four minutes after the interval.
Babel's hopeful clearance was allowed to bounce fatally by Rami and the Spain striker latched onto the long ball before racing into the box and stabbing an angled shot over the diving keeper.
Rami made amends five minutes later when his outstretched leg prevented Gerrard's early cross from finding an unmarked Torres, who would surely have killed off the tie.
To Lille's credit they refused to give up hope and Pierre-Emerick Aubameyang came close to shocking Anfield when he side-footed a flicked-on free-kick narrowly over the crossbar in the 74th minute.
The French club needed to score just once to potentially win the tie on the away goals rule and tension increased among home fans as time ticked away.
Misplaced passes were greeted by groans from the Anfield faithful but, despite enjoying plenty of the ball, the visitors were unable to force Reina into making a serious save.
Dirk Kuyt was twice denied by Landreau inside 60 seconds with long-range drives as Liverpool upped the tempo in the closing minutes.
But it was left to Torres to add a gloss to the final scoreline as he turned the loose ball into the net after Gerrard's low shot in the 89th minute was parried into his path.