Yvan Muller scored his fifth win of the World Touring Car Championship season in race one on the streets of Porto, leading home an all-Chevrolet top four.
Muller led RML team-mate Tom Chilton from start to finish, with Michel Nykjaer third and Pepe Oriola taking fourth in his first race after switching from SEAT.
Gabriele Tarquini had separated the quartet in fourth in his Honda until his turbo blew on lap eight, causing him to stop at Turn 13. On the following lap a recovery pick-up truck came on to the track at the preceding corner, ahead of a pack of cars. Franz Engstler hit the vehicle, reminiscent of his collision with a safety car in Pau in 2009, before Fredy Barth spun on the exit, bringing out the safety car for two laps.
Rob Huff finished as the best non-Chevrolet in fifth in his SEAT, ahead of the Lada of James Thompson. Marc Basseng ran seventh until going wide on the last lap, letting Tom Coronel, Stefano D’Aste and then local hero Tiago Monteiro to beat him to the flag.