Hosts Sunderland made life difficult for the Reds for much of the encounter, but their resilience finally cracked as Torres fired home from outside the area on 83 minutes.
It was sheer joy for Liverpool but met with despair by Sunderland as their grit and determination came to nothing.
To be fair, the warning signs were there before the Spanish striker made the telling breakthrough as Rafa Benitez's side pushed forward time after time in the closing minutes.
The Merseysiders had shown the same sort of attack-minded resolve towards the end of the opening 45 minutes, but drew a blank as the Black Cats' rearguard stood firm.
It wasn't all one-way traffic, however, with the Wearsiders starting the brighter of the two sides.
Whether Benitez's men were still suffering from a Champions League hangover remains open to debate, but their was no question about who came out of the starting blocks quickest.
In fact the Reds could have found themselves a goal down early on had Daryl Murphy managed to get any power behind his header.
The Irishman got up highest to meet El Hadji Diouf's cross, but it was straight at Pepe Reina in the Liverpool goal, although the Spaniard needed two takes to get hold of the ball.
Diouf in particular was a thorn in Liverpool's side in the early stages of the clash, but neither he or his team-mates were able to really threaten the visitors' goal.
To be fair, Liverpool were never that much of a threat themselves in the opening period, being restricted to a couple of long-range efforts from Steven Gerrard which were wide of the mark.
After the break, both sides continued to muster up graft without any real craft and the stalemate looked on the cards.
Questions over the new partnership between Torres and Robbie Keane were left unanswered as the duo seemed the follow each other into space far too often.
One moment in particular highlighted that the understanding between the duo was not quite at full strength.
Sunderland goalkeeper Craig Gordon made a great save from Dirk Kuyt, only for the ball to bounce into the path of Torres who looked certain to score.
However, the striker fired the ball off Keane who had run across his path and the effort deflected wide of the goal.
Luckily it didn't prove costly and the Reds' blushes were spared as Torres came up with the goods to seal a victory and send his side home with the points.