PETRONAS Racing riders Troy Corser and Chris Walker were right on the pace when the World Superbike championship revved into action at Valencia in Spain yesterday.

New signing Walker was fourth after the morning's free practice session, with team-mate Corser just 0.3 seconds and one position back in fifth.

Track temperatures dropped in the afternoon and the FPR boys finished the first day of qualifying in ninth and seventh respectively.

Their best times, however, were set on Pirelli race tyres whereas the rest of the field sliced substantial chunks off their fastest laps on qualifying rubber.

Corser finished with a best lap of 1:37.254, while Walker, on his number two bike, posted a 1:37.718 in the morning session, just one tenth of a second behind his best lap on the FP1 at this circuit.