UAE Team Emirates rider Tadej Pogacar moved up to third in the Tour de France's general classification standings on Wednesday after race leader Julian Alaphilippe was handed a 20-second penalty for illegal feeding at the end of stage five.
Alaphilippe finished safe in the bunch but snatched a bottle about 17km from the line, breaking Tour rules which state that feeding is illegal within 20km of the finish.
"We're checking now but it seems I took a bottle where I was not supposed to," said Alaphilippe, whose error handed the yellow jersey to Briton Adam Yates and saw the Frenchman drop to 16th.
Yates leads Slovenian Primoz Roglic by three seconds in the standings, with Pogacar a further four seconds back.
"Nobody wants to take the jersey like this," Yates said when he found out about Alaphilippe's penalty. "I was on the bus and were about to leave for the hotel when I got a call. I asked Julian and he told me he had a time fine."
Pogacar, 21, retains the white jersey for the Tour's leading young rider, six seconds ahead of reigning Tour de France champion Egan Bernal, following the 183km stage won by Belgian Wouth van Aert.
Van Aert was fastest in the sprint at the end of the ride from Gap that featured no breakaway, an almost unprecedented scenario in normal racing conditions in the modern era.
Dutchman Cees Bol was second and Sam Bennett took third place to become the first Irishman to wear the green jersey for the points classification since Sean Kelly 31 years ago.
"It was maybe the most easy stage I've ever done in a cycling race because no breaks, no high pace," said Van Aert, who on Tuesday did all the heavy work when Jumbo Visma teammate Roglic won the fourth stage.
"But everyone was pressing a lot at the end and it was hectic. I knew it was a stage that suited me and just so happy that I got the opportunity from the team to go for it and to finish it off was sweet," added the Milan-Sanremo champion.
Van Aert's Jumbo-Visma arrived at the Tour as the in-form team with the most powerful looking line-up on the roster, and are the chief challenger to the dominance of Team Ineos who have won seven of the last eight Tours.
Jumbo leader Roglic won Tuesday's stage testing the other overall contenders with his late kick and claiming the stage win atop the climb to an Alpine ski station.
Thursday's sixth stage is a 191km middle-mountain trek from Le Teil to the Mont Aigoual.