The Blues were in action in front of 41,500 passionate fans at the Shah Alam Stadium on Sunday for the second game of their Far East tour.
Veteran goalkeeper Mark Schwarzer made his first appearance in a Chelsea shirt and there was also a start for Burkina Faso teenage midfielder Bertrand Traore.
And it was Traore who opened the scoring after just five minutes, the 17-year-old neatly side-footing home a right-wing cross from De Bruyne.
The second goal arrived on 29 minutes. After a good spell for the hosts, Schwarzer launched a free-kick downfield where Romelu Lukaku flicked on a header for his fellow Belgian, De Bruyne. The attacking midfielder let fly with a fierce shot from 20 yards which rocketed into the roof of the net.
However, De Bruyne was unable to celebrate, instead waving to the bench to signal an injury which resulted in him being stretchered off.
The delay resulted in four minutes of first-half stoppage time being played, long enough for Lukaku to score Chelsea's third goal. He curled home a low shot round the keeper after latching onto Traore's intelligent through-ball through Malaysia's high defensive line.
Only Marco van Ginkel and Eden Hazard stayed on for the second half as Jose Mourinho rang the changes.
As in the 1-0 win over Singha All-Stars in Bangkok in midweek, Wallace made a lively contribution at right-back while Andre Schurrle also impressed in attack.
Some more suspect goalkeeping from Mohd Farizal allowed Victor Moses to notch a fourth goal on 89 minutes after an excellent pass from Josh McEachran.
However, the hosts did register a consolation goal when Moha Fashli Shas headed home in stoppage time. A free-kick from the left side hit Petr Cech's legs and rebounded out to Shas to score from close range.
There was still time for Ashley Cole to make an outstanding clearance, the left-back flicking out his boot to block a goalbound shot.
There appeared to be good news on De Bruyne's fitness at the final whistle. The goalscorer was walking unaided as he went to collect his medal, and Chelsea will hope his injury is not too serious.
The Blues now move on to play an Indonesian All-Stars side in Jakarta next Thursday (kick-off 2.30pm BST).