Adam Yates inherited the yellow jersey of the Tour de France after Julian Alaphilippe was hit with a time penalty at the end of a stage five which was won by Wout van Aert in Privas.
Van Aert won the 183km stage from Gap in a sprint finish but the drama came after the race was over, when commissaires took 20 seconds off Alaphilippe for an illegal feed inside the final 20 kilometres.
The decision saw Mitchelton-Scott's Yates, who began the day four seconds down, elevated into the race lead as he became the ninth Briton in history to don the yellow jersey.
Yates said: "It's not the way I imagined taking the jersey. I'm not even sure what happened to Julian – I heard he got a time penalty for taking a feed late. If I'm honest I don't think anyone wants to take a jersey like this but I guess we'll wear it tomorrow.
"Tomorrow I was looking to try to take the jersey anyway so we'll go in with the same tactics, try and win the stage and see what happens."
There was also an Irishman in green as Sam Bennett, beaten in the sprint by Van Aert, at least did enough on the day to move clear of former three-time world champion Peter Sagan in the points classification.
Alaphilippe's Deceuninck-QuickStep team-mate now leads Sagan by nine points, becoming the first Irishman to wear green since Sean Kelly won the points classification for the fourth and final time in 1989.
News of Alaphilippe's time penalty took some of the shine off Bennett's celebrations in green.
"It's a bit disappointing," he said. "We only heard about it obviously after the finish. It's a bit of the highs and lows today. We thought we'd have yellow and green but unfortunately we don't have it now.
"I'm honoured to wear (green) at least once and I'm really happy that happened today. It's hard to go for stages and the green jersey – today I was so focused on the green I almost forgot to really, really try to win.
"I've never had such mixed feelings in my career. I'm really happy to have green but sad to have lost the stage. But I did everything I could. In the last two kilometres I didn't have the legs to sprint, but I'm pretty happy with my performance in the end."
Yates follows Tom Simpson, Sean Yates (no relation), Chris Boardman, David Millar, Bradley Wiggins, Chris Froome, Mark Cavendish and Geraint Thomas in pulling on the yellow jersey.
The 28-year-old, who will join Team Ineos next season, came to the Tour insisting he would focus only on stage wins after an illness hurt his preparations to have another tilt at the general classification.
