Suzuka WTCC: Jose Maria Lopez leads Friday session for Citroen

Lopez's time of 2m06.987s was 0.791 seconds faster than his nine-time World Rally champion Citroen team-mate Sebastien Loeb, who held the top spot on the timing screens for the final third of the session.

Argentinean Lopez carries a 93-point lead in the drivers' standings over defending champion Yvan Muller into this weekend's penultimate round of the championship. Lopez requires just 17 points from the meeting's potential maximum score of 55 to be crowned 2014 champion.

Lopez would be the first Argentinean to win an FIA world championship since Juan Manuel Fangio's 1957 Formula 1 crown.

Four-time WTCC champion Muller completed a Citroen 1-2-3 on Friday. The Alsace racer was on used tyres throughout the session, and finished a frustrated 1.3s behind Lopez.

"The problem is I can't do what I want to with the car," said the Frenchman.

"It is something to do with the balance. All of the corners here are quite high speed, apart from the chicane, so it is not better or worse in any type of corner.

"It's just like in Shanghai. If it stays like this it will be a very tough weekend for me."

On Honda's home circuit, factory JAS driver Tiago Monteiro claimed fourth and top Civic WTCC honours. The Portuguese former F1 driver was within one tenth of Muller, but some 1.415s adrift of the flying Lopez.

Campos racer Hugo Valente was fastest of the Chevrolets in fifth, ahead of the similar ROAL Motorsport run machine of Tom Chilton.

The session was red-flagged when 2014 WTCC debutant Henry Kwong spun before the long, left-hand, Spoon bend. Kwong's SEAT Leon continued with minimal delay, but soil that had been brought onto the circuit prompted the stoppage.

Shanghai reversed-grid winner Mehdi Bennani had a difficult test, failing to record a competitive time in his Proteam Honda.

"There was a problem in the area of the turbo," explained Bennani's engineer Andrea Cisotti. "We are still taking everything apart piece by piece and investigating."