Rafa Benitez had insisted ahead of kick-off that he had not given up hope of winning the Premier League title and his players responded with a stylish performance as the Blues closed the gap on second-placed Manchester City to four points.
Torres was the star of the show with two goals in the first half, while Juan Mata added a third early in the second half and Adam Johnson's fantastic strike proved to be little more than a consolation for a Sunderland side now in the relegation zone.
Chelsea were quickly into their stride and Eden Hazard had a confident penalty appeal waved away before Torres expertly turned home the Belgian's cross with a well-controlled first-time volley after a flowing move in the 11th minute.
Oriol Romeu soon had to go off through injury and Sunderland started to gain a foothold in the match, with Stephane Sessegnon's ferocious long-range effort stinging the palms of Petr Cech and Craig Gardner also lashing an effort wide.
With Gardner and Johnson starting to make an impression, the Blues were forced on to the back foot at times and, although they tried to hit their hosts on the counter, O'Neill's men were beginning to dominate.
However, disaster struck deep into injury time when Sweden international Sebastian Larsson needlessly brought down Ramires in the area and Torres stepped up to stroke home the penalty.
Any hopes of a fightback were dashed within four minutes of the restart when Phil Bardsley miscontrolled a cross and the ball ran to Torres, who was denied a hat-trick by the crossbar.
Sadly for Sunderland, the rebound dropped invitingly for Mata to make it 3-0 and wrap up the victory with 41 minutes still to play.
It could have been four three minutes later when Mata rolled the ball into the path of Moses, who drilled a right-foot effort wide of the far post.
Sunderland responded and England international Johnson embarrassed keeper Cech with a 66th-minute shot he really should have repelled.
Cech had to produce a number of other saves as the Black Cats tried to get back into the game, while Gardner hit the bar at the death.
However, as a crowd of 39,273 left the Stadium of Light, it was those heading south who were wearing the smiles, leaving those closer to home to contemplate a run which now extends to just two Premier League victories in 23 attempts.