Hazard, who turned 23 on Tuesday, broke the deadlock early in the second period at the KC Stadium before Torres marked his 200th Premier League appearance with a late goal.
Victory moved Jose Mourinho's side into first place above former leaders Arsenal, who visit Aston Villa on Monday, and set them up nicely for next weekend's home game with Manchester United.
Hull had beaten Fulham 6-0 in their previous home game and they had the best of the early skirmishes, with Jake Livermore testing Petr Cech from long range and Yannick Sagbo shooting wide after John Terry lost the ball.
Chelsea began to assert control, however, and Hull goalkeeper Allan McGregor had to produce a razor-sharp reflex save to deny Oscar before tipping a plunging David Luiz free-kick over the crossbar.
McGregor had to repel another free-kick from Luiz early in the second period before Hazard made the breakthrough in the 56th minute with a characteristic individual goal.
The Belgian forward collected a flick from Ashley Cole just outside the Hull area and shifted the ball away from a couple of defenders before drilling a low shot into the bottom-right corner with his right foot.
Torres applied the finishing touch in the 87th minute, gathering a pass just inside the Hull half and wriggling past Alex Bruce before slamming a low shot inside the left-hand post.
Chelsea manager Mourinho dismissed French media reports linking Hazard with a move to Paris Saint-Germain, saying: "The club doesn't want to sell him. Obviously the manager has that decision. Every manager wants players like him.
"Last year you saw a talented Hazard; this year he is a much more mature player. He deserves more than man of the match, probably player of the month. Not many are doing what he is doing."
Sunderland's Johnson hits hat-trick, Everton beat Norwich
Adam Johnson scored the first hat-trick of his professional career as Sunderland won 4-1 at Fulham to climb off the foot of the table and close to within a point of safety.
Johnson teed up Sunderland's other goal, for Ki Sung-yueng, with Steve Sidwell replying for the hosts.
Gareth Barry put Everton ahead in the 23rd minute with a fine 20-yard shot that fizzed into the top-right corner, with Kevin Mirallas adding a free-kick shortly before the hour.
After Palace winger Jason Puncheon horribly miscued an early penalty, Christian Eriksen broke the deadlock in the 50th minute from Emmanuel Adebayor's flick-on.
A day after his imminent move to Toronto FC was announced, Spurs striker Jermain Defoe was granted a warm reception after coming on a second-half substitute and he claimed a well-taken goal with 18 minutes remaining.
West Ham United spoilt Ole Gunnar Solskjaer's first home game as Cardiff City manager as goals from Carlton Cole and Mark Noble gave Sam Allardyce's side a 2-0 win that took them out of the bottom three at their hosts' expense.