Geraint Thomas rode strongly to claim third on the first mountainous stage of the race, behind winner Julian Alaphilippe (Quick-Step Floors), while Moscon dug in to cross the line ninth, eight seconds back.
That moves the young Italian into the overall lead, six seconds ahead of teammates Michal Kwiatkowski and Thomas, who sit second and third respectively after an excellent first five days of the race.
With three categorised climbs to contend with the team rode strongly all day across the 181 kilometre stage, taking up the pace making on the hors categorie Col du Mont Noir just past the midway point.
Tao Geoghegan Hart came to the fore, pushing the tempo on the day’s toughest climb, before leading the way through the valley in pursuit of lone leader Dario Cataldo (Astana).
He and Jonathan Castroviejo dovetailed perfectly on the flat section ahead of the final climb, where Geoghegan Hart produced a brilliant turn on the front of the bunch to reduce Cataldo’s gap to all but nothing.
Then the attacks came and Thomas was able to follow Dan Martin (UAE) as he pushed clear under the flamme rouge. The Welshman played it cool in the final as Alaphilippe sprinted to the victory ahead of Martin, Thomas content with a comfortable third ahead of the bigger days to come.