Torres scored his first goal of the season in the 65th minute, volleying home a Dirk Kuyt cross from the edge of the box.
The performance was far from convincing but Roy Hodgson will be pleased to have got his first league win as Liverpool boss and have Torres among the goals.
Torres was starting up front alongside Steven Gerrard for the first time this season, with Lucas and new signing Christian Poulsen holding the midfield. Meanwhile, another new midfielder, Raul Meireles was unveiled prior to kick off.
BBC Sport Match Report
Spain striker Fernando Torres volleyed in to give an unconvincing Liverpool victory over West Brom at Anfield.
Torres struck his first goal of the season by clinically converting a Dirk Kuyt cross from the edge of the box.
The Spaniard was denied a second when Baggies keeper Scott Carson blocked his far post shot at point-blank range.
The Reds were denied a late penalty for an apparent Gonzalo Jara handball before the visitors had James Morrison red-carded for a tackle on Torres.
The numerical advantage helped the Merseysiders close out the game as they were relieved to record their first league win of the season, albeit courtesy of a rare moment of quality in an encounter which had plenty going on before kick-off.
Liverpool’s new signing Raul Meireles was presented to the crowd and left-back Paul Konchesky was also at Anfield to finalise a proposed move from Fulham.
The arrivals, even though Javier Mascherano is set to leave for Barcelona, will have added to the air of optimism sweeping through Anfield, although the Reds have so far failed to mirror that sentiment with performances and results this season.
And, when the focus of attention switched to the pitch, it was the same again for the home side as the industry of the Baggies served to frustrate a Liverpool side playing like strangers.
The Reds were too pedestrian and predictable and seemed unsure in possession as opposed to a West Brom side who grew in confidence as each of Liverpool’s forward forays continually and harmlessly broke down.
The visitors had a penalty appeal waved away for Martin Skrtel pulling Jonas Olsson, while Torres thought he might have had a spot-kick for his shirt being tugged in the visitors’ box.
Skrtel fizzed a shot just high of the visitors’ goal but, while the Merseysiders were in sloppy mood, the Baggies could not capitalise as Marc-Antoine Fortune had a strike saved and were limited to speculative efforts from distance.
Torres had not scored in 10 games for club and country going into the match and was looking a shadow of his devastating best as he nursed his way back to match fitness from injury.
However, after the Reds survived a scare with goalkeeper Pepe Reina saving from Jara, Torres showed his quality and worth to his team by finishing off a Reds counter-attack with a volley from Kuyt’s cross.
The Spain striker almost added another when found by a Steven Gerrard cross to the far post only for Carson to block his far post strike.
The Anfield side are clearly a work in progress as manager Roy Hodgson reinforces his squad and, in tandem, tries to embed his style on the side.
However, buoyed by the goal Torres thought he should have had a spot-kick when Jara seemed to block his effort with his arm.
Torres was the target of an over-zealous, rather than malicious, challenge which resulted in Morrison being sent off before the home side negotiated some anxious late moments to earn their first three points under manager Roy Hodgson.
Liverpool: Reina, Johnson, Carragher, Skrtel, Agger, Kuyt, Poulsen, Lucas, Jovanovic (Maxi, 59), Gerrard, Torres (Babel, 89)
Subs not used: Jones, Kyrgiakos, Kelly, Spearing, Pacheco