Sept 3 (Reuters) - Spain's Enric Mas extended his overall lead in the Vuelta a Espana with a late attack on his rivals as Slovenia's Jakob Omrzel won stage 12 to Calar Alto on Thursday.
Movistar rider Mas burst out of a chasing group including red jersey contenders Primoz Roglic and Felix Gall with around 13km of the mountainous 166.6-km ride left and powered away.
