An impressive, ruthless performance from Chelsea saw us consolidate our position at the top of Group E, and register our best ever win in the Champions League at Stamford Bridge.
Two goals in the opening 10 minutes, from Raul Meireles and Fernando Torres set the tone for what was to come, and some devastating finishing, particularly in the first half, made it as comfortable an evening as Andre Villas-Boas is likely to enjoy all season. Torres netted again and Branislav Ivanovic and substitute Salomon Kalou also made the scoresheet.
A win in Belgium in a fortnight's time will all but ensure qualification from the group, but Villas-Boas will want his side to finish top of the pile in order to keep away from the big guns in the knockout stages of the competition.
While Barcelona, Real Madrid and the two Manchester clubs hog the limelight, Chelsea will relish their tag as dark horses of the tournament.
Fernando Torres is simply a headline writer's dream, and while he will be disappointed not to have walked away with the match ball, his first-half brace was a timely reminder to his critics that the Spanish striker is slowly but surely recapturing the form which led to Chelsea purchasing his services.
Andre Villas-Boas made six changes from the Chelsea side which beat Everton 3-1 on Saturday. David Luiz replaced captain John Terry in central defence, whilst Oriel Romeu and Raul Meireles came in for John Mikel Obi and the injured Ramires in midfield. Fernando Torres, still serving a domestic suspension, spearheaded the attack, with Florent Malouda on the left and Nicholas Anelka on the right.
Genk were severely depleted, particularly in defence, with captain David Hubert, Jose Nadson, Torben Joneleit and Jeroen Simaeys all missing through injury. On the plus side for manager Mario Been, creative midfielder Daniel Pudil and top-scorer Jelle Vossen, who were both expected absentees, were passed fit and started.
Fernando Torres created the first opportunity of the game in the third minute with a fantastic turn which left two Genk defenders in his wake on the halfway line, before he found Malouda out wide, but the Frenchman's delivery was turned behind for a corner.
Only minutes later the Spaniard could, and probably should, have put the Blues in front, when he was put through by a fantastic flighted ball from Raul Meireles, but Torres could only nudge his effort onto the post.
Chelsea weren't to be denied a minute later, though, when a sublime Meireles effort from just outside the Genk box flew beyond the stranded Laszlo Koteles into the bottom corner to give the Portuguese midfielder his first goal for the Blues.
Four minutes later and the lead was doubled when Torres, intelligently played in by captain for the night Frank Lampard, finished in trademark fashion for his first goal in the competition since he, somewhat ironically, netted against the Blues for Liverpool in the 2008/09 quarter-final at Anfield.
Twenty-year-old Romeu, making his first start in the Champions League for Chelsea, was showing no sign of inexperience or fear in central midfield, orchestrating things effortlessly with a combination of tough tackling and simple, efficient passing.
Florent Malouda, so instrumental down the left in the opening exchanges, should have made it 3-0 in the 22nd minute but he could only steer Torres's cross just past the post.
The Spaniard had his second of the night and Chelsea's third a minute later, expertly getting in front of his man to head home from an exquisite Meireles cross from wide on the right.
The midfield trio of Romeu, Lampard and Meireles were completely running the show, and the injury-ravaged Belgians had no answer for the pass-and-move style of play which Villas-Boas is so keen to implement.
Lampard almost made it 4-0 just after the half-hour mark only to see his header from Torres's cross narrowly miss the target.
David Luiz was then on the receiving end of the type of tackle he is renowned for giving out, before dusting himself down and taking the resulting free-kick, but the flamboyant Brazilian's effort was comfortably saved.
Genk, to their credit, refused to cave in, but their rare attacks often broke down in the final third before they had a chance to test the virtual spectator Petr Cech in the Chelsea goal.
Five minutes before the break, a fantastic counter-attack involving Torres and Lampard came to nothing when Nicholas Anelka, a surprisingly peripheral figure up until this point, shot wide from just inside the penalty area when he should really have done better.
It was 4-0, however, a minute later when Branislav Ivanovic rose above the sloppy Genk defence to head home Malouda's free-kick to end the game as a contest.
With Sunday's west London derby against QPR in mind, Villas-Boas replaced Ashley Cole with Paulo Ferreira at the break, making full use of his favoured rotation policy and giving fringe players some much-needed game time.
Some neat interplay between Bosingwa and Anelka down the right-hand side almost resulted in a chance two minutes after the restart but the veteran forward's inviting delivery was turned behind for a corner.
Thomas Buffel had the visitors' first real sight of goal when he found himself unmarked at the far post, but he dithered on the ball and found his weak effort blocked by Ivanovic.
Torres opted for the spectacular in the 53rd minute when he attempted to turn and volley a floated pass from the technically-gifted Luiz, but the Spaniard failed to connect. Malouda should have scored soon after when he was clean through on goal, but his tame effort was easily stopped by Koteles.
Lampard was then penalised for his honesty in the 58th minute after attempting to stay on his feet when he was clearly fouled in the Genk penalty area. The Blues were again dominating possession but, unlike in the first-half, they lacked a cutting-edge in front of goal.
Jose Bosingwa then tested the palms of Koteles with a stinging effort from distance, but the keeper was equal to it, before Villas-Boas made his second change of the night, replacing Lampard with Salomon Kalou.
The Ivorian striker had to wait only four minutes for his first goal of the season, reacting first and finishing from close range, after Koteles had denied Torres his hat-trick.
Alex then went close with a trademark free-kick from distance with practically his first touch of the ball, but his effort fizzed wide of the post.
As the game petered out into what amounted to little more than a glorified training session for the home side, Malouda met a pinpoint Ferreira cross from out wide on the left, but his header sailed high over the crossbar.
Chelsea (4-3-3): Cech; Bosingwa (Alex 77), Ivanovic, David Luiz, Cole (Ferreira h/t); Meireles, Romeu, Lampard (c)(Kalou 67); Anelka, Torres, Malouda.
Subs not used Turnbull, Mikel, Mata, Sturridge.
Scorers Meireles 7, Torres 10, 26, Ivanovic 41, Kalou 71.
Booked D Luiz (16)
Genk (4-4-2): Koteles; Ngcongca, Masuero (Camus h/t), Tozser (c), Pudil; Buffel, Vanden Borre, Hyland, De Bruyne; Vossen (Nwanganga 80), Barda (Ndabashinze 70)
Subs not used Sandomierski, Derwael, Limbombe, Ogunjimi
Booked Hyland (14), Pudil (41)
Referee Aleksei Nikolaev (Russia)