Two-time reigning champion Muller of France won both races in Monza last month and followed that up by leading from pole position in Spain to take victory ahead of 2009 world champion Gabriele Tarquini (SEAT) in second and Tom Coronel in third.

Muller's Chevrolet team-mates Rob Huff and Menu, having both claimed runner-up spots in Monza, were fourth and fifth respectively in the first race.

Muller felt the hard-fought battle for second spot between Tarquini and Coronel helped his bid for victory.

"I remembered very well that last year Gabriele pipped me at the start, so this time I was absolutely focused on keeping him behind into the first corner," he told the WTCC's official website.

Worried

"I was worried about my tyres, because of the hot temperature and the ballast, but when I saw there was a fight behind I said, 'now it's the time to create a gap'. And then the fight for second place went on and this helped me to increase the gap and save the tyres. It was the perfect scenario for me."

Muller added: "I have the luck of driving the best car of the field, and the whole team are doing a perfect job."

Muller could not continue his winning streak in the second race though as he could only finish eighth as Menu took the victory honours on that occasion.

The Swiss held off a late challenge from Coronel to pip the Dutchman to the triumph, with Italian Stefano D'Aste third in his BMW.

Despite finishing down the order in that race, Muller still boasts a 17-point lead over Menu at the top of the overall standings after the opening two rounds of the season, with Coronel three points further back in third.

Britain's Huff slipped to fourth on 57 points, one adrift of Coronel.