Augusto Farfus posted the quickest time during the opening free practice session for the Portuguese round of the World Touring Car Championship on the streets of Porto.

The BMW Team Germany driver set a time of 2min 10.393secs at the wheel of his BMW 320si to outpace the Chevrolet of Alain Menu and home favourite Tiago Monteiro, who led the SEAT challenge in third place.

Rob Huff was fourth quickest ahead of Alex Zanardi and Gabriele Tarquini as each of the three leading manufacturers placed two cars inside the top six on the times.

Stefano D'Aste led the Independent runners with the tenth quickest time overall ahead of Tom Coronel and points leader Felix Porteiro, while the new LADA in the hands of James Thompson completing nine laps as the Briton battled fuel pressure problems - leaving him down in 23rd. Team-mate Jaap van Lagen failed to set a time after gearbox problems left him in neutral and forced him to go off into the wall.

The session was briefly halted after an advertising banner fell onto the circuit.