Chevrolet dominated the Friday test session for the WTCC Race of Portugal on the streets of Porto, with championship leader Rob Huff fastest.
Huff and teammates Yvan Muller and Alain Menu traded fastest times during the first half of the session, where the trio were around two seconds quicker than anybody else.
They remained unchallenged in the second half of the session, with Huff emerging as the fastest. He was six tenths quicker than Menu's best, with Muller a further nine hundredths slower.
The session came to an early conclusion when Robert Dahlgren's Volvo hit the barriers and came to a halt bringing out the red flags for the final few minutes.
Norbert Michelisz was the best of the rest in his Zengo BMW, 1.5 seconds off Huff's benchmark.
Stefano D'Aste was an outstanding fifth on his return to the WTCC – the test session being his first drive of the Wiechers-Sport BMW 320 TC that had been at the tail of the field so far in 2011 in the hands of Urs Sonderegger. D'Aste had been the class of the independents' field on the most recent visit to Porto in 2009.
Two more BMWs were next up, with Proteam's Mehdi Bennani in sixth ahead of Tom Coronel's ROAL car. Pepe Oriola was the best of the SUNRED cars in eighth, with Dahlgren and Michel Nykjaer rounding out the top ten.
Local star Tiago Monteiro was only 16th quickest, but teammate Gabriele Tarquini only managed four installation laps in his Leon with no time set due to technical problems.