Britain's Stevie Williams (SEG Racing Academy) fought off pressure on the final stage of the 2018 Ronde de l'Isard to take the overall victory.
The 21-year-old had won the first two stages of the four-day race in the Pyrenees, winning on the first day's summit finish to Eycheil before taking the victory the next day on the mountain top finish at Goulier Neige.
After a flatter stage to Boulogne-sur-Gesse on stage three, Williams led the race overall ahead of Belgium's Julian Mertens (Lotto-Soudal U23) at 23 seconds and Aurélien Paret-Peintre (Chambery Cyclisme Formation) by 28 seconds with one stage remaining.
On the final stage, a 152.4km route from Salies-du-Salat to Saint-Girons with three mountain passes, Williams saw future Ag2r La Mondiale professional Paret-Peintre pose the biggest threat to his overall lead.
The stage itself was taken by Switzerland's Gino Mäder (IAM Excelsior Cycling Team), no threat to the overall, who went solo in the descent of the Col d'Agnes at around 50km remaining.
Behind though, Paret-Peintre attacked with his team-mate Clément Champoussin on the descent of the Mur de Péguère with around 20km to go.
Williams, chasing in the yellow jersey, was blighted by two punctures as the French duo rode out in front, while second overall Mertens suffered a crash on the technical descent.
While Paret-Peintre was able to drag a gap out to 25 seconds on the descent, the flatter run to the finish saw the gap come right back. It was just two seconds as both groups crossed the finish line over three minutes down on the stage winner, meaning Williams secured the overall by a gap of 20 seconds.
"I am over the moon" Williams said. "It's unbelievable to win such a big race after an epic final stage. It's not an easy win and it will gave me some self-confidence in my career."
Williams, from Wales, will move up from the under-23 ranks next year with the win in the Ronde de l'Isard by far his best result of his young career.
Having ridden for JLT-Condor for a year in 2016, Williams' best results before this week were a second place in the Flèche Ardennaise in 2017 and third in the New Zeland Cycle Classic in 2016. He also placed ninth in the U23 Liège-Bastogne-Liège earlier this year.
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Follow on Twitter: @richwindy
Richard is digital editor of Cycling Weekly. Joining the team in 2013, Richard became editor of the website in 2014 and coordinates site content and strategy, leading the news team in coverage of the world's biggest races and working with the tech editor to deliver comprehensive buying guides, reviews, and the latest product news.
An occasional racer, Richard spends most of his time preparing for long-distance touring rides these days, or getting out to the Surrey Hills on the weekend on his Specialized Tarmac SL6 (with an obligatory pub stop of course).
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