Alex Zuelle extended his overall lead to 36 seconds from fellow Swiss rider Laurent Dufaux by opening a gap of four seconds over Dufaux in the last 300 metres in yesterday's mountain stage of the Tour of Spain.
Spain's Roberto Heras scored the first victory of his three-year professional career at the summit of El Morredero.
He finished the 142-km stage from Leon 30 seconds clear of another Spanish rider, Jose Jimenez, with Switzerland's Pascal Richard third.
Heras overtook Jimenez four km from the finish of the stage with the main contenders, led by Zuelle, trailing by more than 90 seconds.
The top three in the overall rankings were unchanged with world time-trial champion Zulle and closest rivals Laurent Dufaux of Switzerland and Spain's Fernando Escartin finishing in a tight clutch of riders more than a minute behind Heras.
"I'm very happy," said Zulle afterwards. "I feel fine having had the rest day. I wasn't afraid but I had a lot of respect (for the course) as I didn't know this mountain (Morredero)."
The Tour continues today with a 196 kilometre run from Ponferrada to Valgrande Pajares.
