The Lotto-Dstny rider, a former one hour world record holder, in many ways shared the limelight Thursday with the 20km long artificial lake Serre-Poncon with turquoise blue waters that run off the Alps to 90m deep in spring.
This was an opportunity for the lesser mortals to take centre stage on a Tour dominated by a tense tussle for the title, with one-day specialists jostling to get in the breakaway.
Thirty of them battled around a series of lake resorts cheered on by holiday crowds with 22km of categorised climbs that splintered the escape into mini groups in pine-wooded hills that spared them some of the sizzling 33 Celsius (91 Fahrenheit) heat.
On a stage billed as the prettiest on the route Norwegian Tobias Johannessen of Uno-X fell on a tight downhill corner overlooking the lake, but avoided the disaster of plunging into a ravine.
Eritrean break out star Biniam Girmay retained the green sprint jersey ahead of Jasper Philipsen as the escape group took the intermediate sprint points way ahead of the peloton.