Torres - who bagged a treble against Middlesbrough last month - grabbed the opener for Liverpool with just eight minutes on the clock courtesy of an expert finish from the Spaniard. Dirk Kuyt whipped in a low ball from the right wing and Torres stole a yard on Anton Ferdinand to crack the ball home on the turn from inside the box for his 22nd goal of the season.
West Ham should have equalised after 13 minutes when Luis Boa Morte was played in on the left and rounded the on-rushing Jose Reina but from a tight angle his shot was hooked over his own crossbar by Alvaro Arbeloa.
Torres had to wait until 61st minute to make it 2-0. The Spain international was on the end of another cross from Kuyt - this time heading beyond Robert Green into the top corner.
Torres almost grabbed his hat-trick minute later but his firm header from Steven Gerrard's cross hit the post and trickled along the line, but he was not to be denied.
Torres made it 3-0 when he flicked the ball past Lucas Neill before sliding the ball into the corner and moments later Gerrard grabbed Liverpool's fourth. The England man was allowed to advance to the edge of the penalty area before rifling the ball into the top corner.