(Ed: Viviani was relegated for an “incorrect sprint” after the finish of the stage)
The Italian from Deceuninck-Quick-Step beat Fernando Gaviria (UAE Team Emirates) and Arnaud Demare (Groupama-FDJ) in the gallop to the line of the 220km stage that started in Vinci.
Yesterday’s winner Pascal Ackermann (Bora-Hansgrohe) did not have enough firepower on the flat run-in and finished just off the podium in fourth.
Earlier, Sho Hatsuyama (Nippo-Vini Fantini-Faizanè) of Japan got reeled in by the peloton with 75km remaining after a breakaway of 144km in which he had established a maximum lead of 7:10.
Primoz Roglic (Jumbo-Visma) retained the pink jersey he won after destroying his main general classification rivals in Saturday’s 8km time-trial. The Slovenian leads Simon Yates (Mitchelton-Scott) by 19 seconds with Vincenzo Nibali (Bahrain-Merida) a further four seconds in arrears.
Other pre-race favourites, Miguel Angel Lopez and former champion Tom Dumoulin, are both 28 seconds adrift in fourth and fifth respectively.