But the Spanish hitman came off the bench to break the deadlock with ten minutes on the clock and skipper Steven Gerrard sealed a 2-0 win with a penalty at the death.
Benitez sprang a surprise by naming an unchanged side from that which demolished Besiktas 8-0 in midweek. Even Peter Crouch, expected to make way for Torres despite netting two against the Turks, kept his place.
Liverpool started with intent with Crouch and Andriy Voronin linking well up front and the marauding Gerrard dictating play in midfield.
And it was the skipper who nearly opened the scoring on 12 minutes after a slick move down the right wing, but his curling shot from the edge of the box flashed over the bar.
Fulham started quietly but came close to taking a shock lead a minute later as Danny Murphy almost marked his return to Anfield with a dipping volley which forced Jose Reina into a smart save diving to his left.
Lawrie Sanchez's men were happy to let Liverpool try to break down an 11-man defensive wall and hit the Reds on the break.
But the Londoners were lucky to go in level at the break when a looping Crouch header struck the underside of the bar with seconds remaining.
Liverpool sprang out the blocks quickly as the lively Voronin forced a save out of Niemi with a low volley.
Gerrard was then felled by ex-midfield partner Murphy after another surge goalwards and Fabio Aurelio's wickedly bent free-kick was parried by Niemi, but Yossi Benayoun poked the follow-up over.
A minute later Voronin skipped past the Fulham defence and fired in a fierce shot which Niemi did well to tip over.
The Kop sensed blood as Liverpool drove forward with intent but could still not break the deadlock, Niemi this time denying a deft Benayoun chip on 62 minutes with a fine tip over the bar.
Benitez had already brought on midweek two-goal hitman Ryan Babel when he signalled to Torres to strip off his tracksuit to the Kop's roar of approval on 69 minutes.
It proved a wise move 11 minutes later when the Spaniard chested down a hopeful Reina punt forward, twisted and turned his way into the box and coolly slotted home at the near post, with Niemi hopelessly flat-footed.
Four minutes later it was game over. Crouch was brought down in the box and Gerrard placed the penalty in the corner with Niemi going the wrong way.