Jonathan Rea led the way following the opening two practice sessions ahead of the third round of the World Superbike Championship.
The current championship leader has won three of the opening four races of the season and edged out Kawasaki team-mate Tom Sykes to go into Saturday's third session - with a gap of just 0.145 seconds splitting the top two.
Sykes had looked like getting the better of his fellow Brit, but Rea put in a best time of one minute 51.234 seconds to come out on top at MotorLand Aragon in Spain.
The Ducati of Chaz Davies had clocked the fastest time in the morning and was still able to remain in the top three after the second run, with his team-mate Xavi Fores taking fourth.
Leon Haslam in fifth was the last man to get within a second of Rea for Aprilia, with the Suzuki of Alex Lowes in sixth.
Reigning champion Sylvain Guintoli could only manage a time to see him go ninth quickest, behind team-mate Michael van der Mark and Nico Terol of Althea Racing, whilst Spanish fans saw Rubi-born Jordi Torres break into the top 10 for Aprilia.