Belgian 20-year-old Remco Evenepoel won the Tour of Burgos on Saturday after doing enough in the final stage to hold onto his overnight lead.
It was the third Tour win of the season for the former footballer tipped for the very top and who will race his first Grand Tour at the Giro d'Italia in October.
"Mission accomplished," pre-race favourite Evenepoel said on the podium. "I had to suffer, I had to fight, and now I feel great."
Saturday's stage, which ended with a summit finish at Lagunas de Neila, was won by Ineos' Colombian climber Ivan Sosa, who crossed the line alone after an attack in the last kilometre.
Sosa won the last two editions but struggled on the race's previous summit finish.
"Obviously I know this climb well, I wanted the third title and once that wasn't possible I wanted the stage," said the 22-year-old Sosa.
"We were all on the edge and I'm really happy with the final outcome."
Local challenger Mikel Landa almost grabbed overall victory with a relentless attack on Evenepoel, who hung on in the last stretch of the climb to win the race he has led since stage three.
Evenepoel finished the final standings 30 seconds clear of Landa, with Joao Almeida third at 1min 12sec.
Earlier in the season, Evenepoel won the Tour of the Algarve and the Tour of San Juan.