MARKINA-XEMEIN, Spain (AP) -- Alberto Contador protected his lead of the Tour of Basque Country before the decisive time trial, while Ben Swift of England won Friday's fifth stage.
Swift edged a small group of riders at the finish line to claim the 160-kilometer (99-mile) leg featuring five categorized mountain climbs from Eibar to Markina-Xemein in just under four hours.
"This was one of my best" days, said Swift, who rides for Team Sky. "It was really hard, but the legs felt very good. I liked my chances doing into that sprint."
Alejandro Valverde, who is second overall, also finished second in the stage, a wheel-length behind Swift. Contador, a five-time Grand Tour winner, finished in the leading group to make sure he didn't lose any of his 12-second lead.
Contador will be seeking his third Tour of Basque Country title when the 54th edition of the six-day race in northern Spain concludes on Saturday with a 25.9-kilometer (16-mile) time trial to and from Beasain.
Valverde launched an attack with less than 10 kilometers to go, but Contador stayed pegged to his nearest challenger as they sailed down a long downhill stretch before being caught by the pack.
"I had to try it, even though we knew it was going to be tough," Valverde said. "It will be a hard time trial, especially if there is more wind against us like today."
Contador described his two-man battles with Valverde throughout the race as the two Spaniards "playing cat and mouse."
"I will treat (tomorrow's time trial) as if we had the same time," Contador said. "It is true I have a 12-second advantage, but I still think it is a very open race."