The Spaniard took his tally to five goals this season as he once more demonstrated his extraordinary value to Rafa Benitez's fragile team, securing all three points on an evening which might have prompted obituaries for Liverpool's title hopes.
As it is, they climb to third in the table for now and may reflect on a job well done, even if they looked utterly unnerved at times by the pace of 20-year-old Zavon Hines, making only his second appearance for West Ham.
1-0: Torres concludes a dazzling run with a clinical finish to beat the lunge of Matthew Upson and Robert Green at his near post
When Torres settled the game for Liverpool on 75 minutes, West Ham had been enjoying a fine period. Having twice come from behind to level the scores, the home side might even have dreamt of a famous victory, with the verve of Hines and the strength of Carlton Cole offering some hope for a long season ahead.
Hines had the first of many clear chances in the second minute. Martin Skrtel got in a tangle and while Jamie Carragher dawdled, Hines nipped the ball away and sprinted goalwards. The youngster struck it firm and true and his shot beat Pepe Reina but rebounded off a post into the keeper's arms.
When Hines was then denied only by the late intervention of Glen Johnson after 11 minutes, an enormous roar echoed around Upton Park. Yet, this West Ham team are too na? to sustain such intimidation.
On 20 minutes, they fell behind moments after breaking with menace on their own counter-attack. Hines failed to complete a simple pass to Alessandro Diamanti and it took only a few seconds between Emiliano Insua robbing the Italian and Torres crashing in the opener.
It was a magnificent effort, the Spain striker receiving the ball on the edge of the area and transfixing James Tomkins with two stepovers and a burst of pace which took him past the defender with ease before striking from a tight angle inside Robert Green at the near post.
It was a bitter blow for the Hammers, only exacerbated by the departure of an injured Matthew Upson on 24 minutes. There was a further blow when long-term absentee Valon Behrami, back after six months out with knee and back trouble, also made an early exit.
Penalty fine: Jamie Carragher was adjudged to have fouled Zavon Hines to present West Ham with a spot kick
But Hines was irrepressible, attacking with a vigour that constantly unsettled Carragher.
On 29 minutes Hines pushed the ball past the Liverpool defender, who was embarrassed for speed, nudging the youngster in the back. Hines went to ground and referee Andre Marriner awarded the penalty and booked Carragher.
Nice trip: Alessandro Diamanti scores his penalty in the 29th minute, despite a stumble
Up stepped Diamanti, 26, making his home debut. Signed from Livorno in the window, he did not take the stage like a man content to sneak into the club unannounced, grabbing the ball and marching up to take his penalty. Mark Noble, the regular taker, did not get a look in.
Seconds later Diamanti was celebrating with gusto, unperturbed by the fact that he had slipped on his backside while striking the spot-kick high past Reina, who protested in vain that he had taken two touches.
But on 42 minutes, West Ham were again undone by abysmal defending.
All white: Liverpool players celebrate Kuyt's strike
Yossi Benayoun, like colleagues Johnson and Javier Mascherano back at their old club, struck a wellflighted corner towards the head of Steven Gerrard. Substitute Radoslav Kovac - on for Behrami - neglected to challenge and Gerrard headed the ball towards the bottom corner, where Dirk Kuyt turned it in.
Liverpool, though, are quite capable of matching that level of incompetence when it comes to defending corners. Carragher and Torres looked bewildered as they patrolled their zones, neglecting to challenge Cole as he rose to head Noble's kick home on the stroke half-time.
Thunderbolt: Carlton Cole leaps above the Liverpool defence to equalise for West Ham
Skrtel and Mascherano made clumsy fouls on Hines which earned yellow cards and the Jamaica-born south Londoner linked well with Cole, who muscled past Sktrel and Carragher only to see his shot deflected away. Diamanti's corner on the hour seemed to be curling into goal until a desperate Reina touched it wide. Cole led the charge now, with Scott Parker and Noble his willing infantry, and Gianfranco Zola's men seemed the more likely to win it.
But they were undone by the great Torres. Ryan Babel struck a decent cross and Torres, hungrier to meet the ball, rose above Tomkins and Faubert to strike the decisive blow.
Match winner: Torres scores his second
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