Tour de France leader Bradley Wiggins is aiming to all-but confirm his place as the first British winner of the yellow jersey.
The 53.5-kilometre stage 19 time-trial from Bonneval to Chartres was set to provide an opportunity for Wiggins to demonstrate his supreme talent against the clock and enhance his commanding lead in the maillot jaune ahead of the final day, which is traditionally a procession to Paris for the Tour leader.
Wiggins played an integral role as Cavendish claimed a 22nd sensational stage win of his remarkable career and a second of the Tour.
Wiggins said: "He's been an incredible team-mate the last couple of weeks. It's nice to be able to pay him back.
"It's been hard every morning, thinking about the GC (general classification) and maybe sacrificing some sprint stages.
"Nine times out of 10 Cav finishes it off when you do something like that.
"And once again he showed, if there was any doubt, that he is the fastest man in the world."