Ireland's Daniel Martin claimed the overall lead of the Volta a Catalunya after Alejandro Valverde crashed out of first place midway through Thursday's 217.7km stage to a summit finish at Port Aine-Rialp.
Valverde took over at the top of the general classification with a second-placed finish on Wednesday but abandoned the race after he and Movistar team-mate Eros Capecchi came to grief this time.
Garmin-Sharp's Martin was part of a 25-man breakaway group which formed early, and was the only one not caught by the peloton before the finish.
He finished 36 seconds ahead of 2010 champion Joaquim Rodriguez, who is also second overall, 10 seconds back.
Martin also catapulted himself ahead of Sir Bradley Wiggins in the GC, with a sixth-placed finish for the Tour de France winner dropping him down to fourth overall.