The 213.5-kilometre flat route from Reims to Nancy did not pose any major difficulty and was a ideal opportunity for sprinters to get a stage win, a day after Viviani's teammate Julian Alaphilippe seized the yellow jersey with a solo effort.
"No one wins the Tour on five-second sprint finishes but obviously it would be better not to have lost that", Thomas said. It was the big goal of the year.
"I won in the Giro and the Vuelta and now in the Tour de France, that means a lot to me".
"I heard people say my name every 10 seconds, it's a day I will never forget", world number one Alaphilippe, who previous year won the mountains classification and claimed two stage wins, told reporters.More news: Arsenal captain Laurent Koscielny refuses to join pre-season tour
Viviani now wants more stage wins, he is not satisfied with just one, even if he knows he will have to play a team role in the next two mountain stages and pay Alaphilippe back by helping to defend the yellow jersey.
"I think way too much has been made of it", he said.
The Italian speedster might soon be racing without his favourite teammates, however, amid reports he might join Cofidis next season as the French outfit seeks to replace its top sprinter.
After Alaphilippe led the Deceuninck-Quick Step train to the front, Max Richeze and Michael Morkov set a very fast tempo to launch Viviani's final acceleration.
But Viviani was indebted to Alaphilippe, who rode as his pilot fish while also maintaining his race lead and who, for the moment, seems unable to do any wrong, either on the road or in the French media.More news: Nintendo’s New Puzzle Game ‘Dr Mario World’ Launches on Android, iOS
It was Alaphilippe's first stage victory at this Tour and third in his career. After several dozen fans greeted him at his team hotel in the morning, supporters lining streets across the small villages of eastern France wildly cheered him on, shouting "Loulou, Loulou!" - the Frenchman's nickname.
The main contenders, including defending champion Geraint Thomas, had a quiet day in the peloton.
Thomas remains 45 sec adrift of Alaphilippe in the overall standings.
"The team has been fantastic".
"I enjoyed every kilometre today and at the end we got a attractive victory so it was awesome", Alaphilippe said. "It's been ideal", Thomas said.More news: Trump defends cabinet member embroiled in Jeffrey Epstein sex-abuse case
- Roof-top stork's nests - A trio adventured out on a long-range breakaway early in the stage. with Michael Schar being awarded the combativity award after he, Frederik Backaert and Yoann Offredo held on until the Nancy city limits.