Cavendish, of the Omega-Pharma team, finished over a bike length ahead of Edvald Boasson Hagen (Sky) and Slovakian Peter Sagan (Cannondale) in a reduced bunch sprint after they had avoided a crash inside the final kilometre.
It was the Isle of Man rider’s 24th stage win on the race. On what was the second-longest stage (228.5 kilometre ) of the 100th edition the peloton gave the green light to an early six-man breakaway which formed in the opening kilometres after Belgian Thomas De Gendt had gone on the attack.
By the 37km mark they had built a maximum lead of nearly 13 minutes on the main peloton, which only really decided to start the chase with a little over 100km remaining.
With Gerrans in the race leader’s yellow jersey, Orica-GreenEdge spent long spells leading the bunch but with a stage win on a flat home straight up for grabs the other teams with top sprinters soon began sending riders to the front to boost the chase.
Sixty kilometres from the finish the lead had halved to just over six minutes and 10km further on the lead group was split in two as De Gendt, Yukiya Arashiro and Alexey Lutsenko — a former under-23 world champion who is making his race debut with Astana — left their companions behind.
Not wanting to miss out on contending a possible stage win, Arashiro’s Europcar teammate Kevin Reza, dug deep to bridge the gap.
The quartet’s lead over the main bunch, however, had been trimmed to 5:05 with 40km to race as riders from Argos, Lotto, and Omega-Pharma joined Orica in the hunt.