Plancher-les-Mines - Simon Yates rode into the Tour de France young rider's white jersey on Wednesday and then set his sights on emulating twin brother Adam.
Last year, Adam Yates won the white jersey after he ended a stunning Tour performance in fourth overall.
And this year, after the first mountain top finish, Simon Yates took that same jersey after a sixth-place finish behind stage five winner Fabio Aru of Italy moved the Briton up to sixth overall.
"Of course there's a lot of strong guys still not really that far behind me so it's going to be difficult to try to keep a hold of it (the white jersey), but I'll give it my best shot," said Yates, who took an impressive sixth place at last year's Vuelta a Espana and was second to Australian Richie Porte at the Tour of Romandie earlier this year.
His brother Adam isn't riding the Tour this year having finished ninth at May's Giro d'Italia.
But if Simon Yates, 24, is to keep hold of the white jersey all the way to Paris, he says he will need to be careful on the flat or transitional hilly stages.
"I have to be cautious. Always on the front foot. Never try to get caught out," he added.
"There's a lot of intermediate stages, maybe some wind and I'm only a small guy, so it's difficult for me to be there with the big guys fighting it out in the crosswinds or whatever."
But having showed on Wednesday he has good climbing legs, Yates should be able to stick with the overall contenders in the mountains.
Another rider who did that was Ireland's Dan Martin, who finished second, 16 seconds back from Aru and moved up to fourth overall, just 25sec behind reigning champion Chris Froome, who took the yellow jersey off his Sky team-mate and British countryman Geraint Thomas.
"I'm gutted to not win again, but we're getting closer," said Martin, who was third on Monday's third stage.
"It was a really good performance. It was just unlucky that Fabio got a gap there, he was super strong."
Martin had a great Tour last year, running third during the middle section before struggling on Mont Ventoux and eventually finishing ninth.
But last month he edged Froome off the podium at the Criterium du Dauphine and has started in fine form again.
Two-time former winner Alberto Contador wasn't in quite such great shape, though, and struggled home in eighth, 26sec behind Aru, although it allowed him to move up to eighth overall at 54sec off Froome.
"Today, the important thing was to save the Tour because I wasn't feeling very good," said the 34-year-old Spaniard.
"It's true that there were time differences and that's never good, but we saved the day more or less and now we have two more days (of flat stages) to get better."
Another to struggle was Nairo Quintana, the runner-up to Froome in 2013 and 2015, who finished ninth at 34sec and now stands ninth overall at 54sec.
But the stage finale was not to his strengths and he was remaining positive.
"The aim was to not lose time in the finale, although I lost a little bit," said the Colombian.
"I tried to lose as little as possible.
"However, we're only in the fifth stage and I hope to get better going forward because my body is still recovering from the Giro."
Quintana finished second to Dutchman Tom Dumoulin at the Giro, which finished six weeks ago.
Top contenders rarely attempt the Giro-Tour double but Quintana is doing so this year as he and his team believe he rides better in his second Grand Tour of the year than his first.