Their reward for a dominant first-half display was a two-goal lead. Thiago Silva, one of four changes, delivered a fine cross which was converted by fellow defender Andreas Christensen on the volley, as the 25-year-old finally celebrated his first goal for the club in his 137th appearance.
Chelsea continued to play at a high intensity and were awarded a penalty when Lukaku was brought down by Lasse Nielsen's scissor tackle, which subsequently forced the Belgian off. Jorginho converted from the spot.
And yet the hosts continued to play with a swagger as the makeshift strikeforce combined for Chelsea's third. Callum Hudson-Odoi - the replacement for Werner who limped off with a hamstring injury - drove forward and played a reverse pass into the feet of Kai Havertz - Lukaku's replacement - and the Germany international made no mistake for his second goal of the season.
Goal number four followed swiftly as Jorginho once again displayed his remarkable penalty-taking ability when he slotted home from the spot after Antonio Rudiger was upended in the box.
The victory keeps Chelsea second with six points, three behind Juventus who beat Zenit St Petersburg 1-0 in Russia. Malmo remain bottom without a point or a goal scored.
TALKING POINT - Injuries mean all eyes fall on Havertz
Chelsea were back to their best as they tore their opponents to shreds courtesy of a thoroughly professional performance. However, the talking point is clearly the injuries suffered by Lukaku and Werner, and what it means for the immediate future.
LONDON, ENGLAND - OCTOBER 20: Romelu Lukaku of Chelsea is treated for injury during the UEFA Champions League group H match between Chelsea FC and Malmo FF at Stamford Bridge on October 20, 2021 in London, United Kingdom. (Photo by Marc Atkins/Getty Image
Image credit: Getty Images
The Blues may be forced to play without a recognised striker for a couple of weeks, if not longer depending on the severity of the knocks. The responsibility will fall largely on the shoulders of Havertz, who before this game only had one goal to his name this season.
His impressive display will boost his confidence but there are much more sterner tests than Malmo to follow.
MAN OF THE MATCH - Jorginho (Chelsea)
Aside from tucking away two cool penalties, the Italian was generally excellent in midfield alongside N'Golo Kante, who was almost as equally impressive.
LONDON, ENGLAND - OCTOBER 20: Jorginho of Chelsea celebrates with Antonio Ruediger and teammates after scoring their team's second goal during the UEFA Champions League group H match between Chelsea FC and Malmo FF at Stamford Bridge on October 20, 2021 i
Image credit: Getty Images
Chelsea: Mendy 6, Rudiger 7, Silva 7, Christensen 7, Azpilicueta 6, Jorginho 8*, Mount 7, Kante 8, Chilwell 7, Lukaku N/A, Werner 6.. Subs: Alonso 6, Saul 6, Hudson-Odoi 8, James 6, Havertz 7.
9' - GOAL! Chelsea 1-0 Malmo (Andreas Christensen): Malmo make a mess of trying to clear Jorginho's corner delivery. The ball bounces around the box before falling at the feet of Thiago Silva on the right. His floated cross finds Christensen unmarked and the defender finishes like a striker, volleying into the corner, to give Chelsea lift-off!
21' - GOAL! Chelsea 2-0 Malmo (Jorginho, pen): Cool as you like, Jorginho slams the spot-kick into the back of the net. And there wasn't even a sign of his trademark skip in the run-up!
48' - GOAL! Chelsea 3-0 Malmo (Kai Havertz): Having committed bodies forward, Malmo lose the ball and Chelsea break rapidly. Hudson-Odoi drives forward with a menacing run and his reverse pass hands Havertz a wonderful opportunity and he makes no mistake, burying the ball into the corner of the goal. It's just his second goal of the season!
57' - GOAL! Chelsea 4-0 Malmo (Jorginho, pen): No mistake from Jorginho, who nets from the spot for the second time this evening! Unlike his first attempt, this time there is a skip in his run-up, as he waits for the goalkeeper to commit before shooting straight down the middle of goal.
No Chelsea player has scored more times for the club under Thomas Tuchel in all competitions than Kai Havertz (six, level with Mount).
Andreas Christensen scored his first ever goal for Chelsea in what is his 137th competitive appearance for the club. He is Chelsea's 14th different goalscorer in all competitions this season.