French rider Randy de Puniet emerged on top of the time sheets during the second day of the MotoGP test at Jerez on Thursday.
De Puniet, riding the hybrid Aprilia CRT RSV-4, posted the fastest lap of 1m 41.5secs, over a second quicker than Texan Colin Edwards on the NGM Forward Racing Suter/BMW.
The Bridgestone-shod machine RSV-4 is the same bike tested by ex-MotoGP rider and current Aprilia test rider Alex Hofmann at the Ricardo Tormo circuit last week in Valencia.
De Puniet is using the test at Jerez to get a feel for the capabilities of the Aspar Team's RSV-4, which will form the basis of the team's development work on the CRT being primed for the MotoGP class in 2012.
Third fastest was Ivan Silva on the FTR BQR Kawasaki (1m 43.5secs) with Spanish national champion Yonny Hernandez, also BQR Kawasaki-mounted, in fourth, a further 0.5secs adrift.
World Superbike Champion Carlos Checa and Franco Battaini were aboard Ducati's MotoGP GP12 machines in the absence of Valentino Rossi and Nicky Hayden.
Rossi has other commitments as he participates in the Monza Rally Show this weekend while Hayden is recovering from a recent wrist operation.
No official times were released for Ducati replacements Checa and Battaini at the test.