Jason Plato topped the times during free practice for the Dunlop MSA British Touring Car Championship season finale at Brands Hatch.
Despite maximum ballast on his car, Plato posted a best time of 48.634secs during the second session, which proved to be just enough to edge out his Chevrolet team-mate Alex MacDowall at the head of the timesheets.
Rob Collard was third quickest for WSR with Steven Kane in fourth, with two more of the title contenders in fifth and sixth; Gordon Shedden just ahead of Tom Onslow-Cole.
Tom Chilton was seventh ahead of James Nash and Mat Jackson, with Matt Neal rounding out the top ten. Neal has spent the opening session of the weekend evaluating new bodywork on the front of his Honda but then elected to switch to the older bodywork for the second session.
Outside the top ten, Sam Tordoff was an encouraging 15th for Triple Eight and within a second of the quickest time while James Thompson gave a public debut to the new NGTC-specification Toyota Avensis and was 17th fastest as he took part in the two practice sessions with the car. Thompson is also due to complete a demo run on Sunday.
Elsewhere, Ben Collins endured a difficult start to the weekend as he suffered gearbox problems on his Airwaves BMW and was forced to sit out the second session, while David Pinkney has been ruled out of Finals Day after an engine issue on his Vauxhall Vectra.
Andy Neate suffered an off in first practice that saw him go into the barriers at Clearways while Shaun Hollamby caused a stoppage in the second session when he went into the Paddock Hill gravel trap.