Torres appeared off the bench just after an hour to see off a determined Wigan side who should have levelled David N'Gog's early strike.
N'Gog struck after eight minutes, heading past Chris Kirkland to give the Reds the lead, but Hugo Rodallega, Paul Scharner and Jason Scotland all missed good chances to level.
But Torres, so often Liverpool's saviour, came off the bench and collected a rebound off his own strike to finally put Wigan to bed despite Charles N'Zogbia's late goal.
Liverpool started like a house on fire with defender Daniel Agger firing wide in just the third minute.
Wigan failed to heed the warning and within two minutes Dirk Kuyt flashed an effort narrowly wide of Chris Kirkland's post before weekend goal-hero Maynor Figueroa dived in to deny the Dutch striker on eight minutes.
But within 60 seconds Liverpool were ahead when Fabio Aurelio crossed for N'Gog to head home his sixth goal in eight starts.
Scharner, who has been heavily linked with a January move to Fulham, produced Wigan's first effort on target when he stung the palms of Pepe Reina in the 11th minute.
Kuyt forced Kirkland to save again before Spaniard Jordi Gomez forced countryman Reina to block his 27th minute effort.
Just five minutes after the break N'Zogbia responded to his manager's team talk by firing an early warning shot at the Spanish 'keeper.
Scotland, signed from Wigan boss Roberto Martinez's former club Swansea in the summer, smashed wide in the 62nd minute.
In response to the pressure Rafa Benitez introduced Torres and the former Atletico Madrid man would ultimately have the final say.
Scharner and Rodallega both wasted good chances for the visitors before Torres bagged his 35th goal in 37 appearances at Anfield by collecting Titus Bramble's deflection and firing home.
Despite N'Zogbia firing home at the death, Liverpool held on.