Jason Plato set a blistering pace in British Touring Car Championship practice at Silverstone as the RML Chevrolet squad took the top two places on the timesheets.
Plato, the 2001 series champion, had been shaded by his teammate Mat Jackson in the morning session, but jumped to the head of the leaderboard in the afternoon, improving his time by half a second and lapping in 1m00.625s in his Lacetti -- 0.3s under the lap record.
Jackson backed him up in second, 0.129sec slower, while championship leader Colin Turkington was next up in his WSR BMW.
James Nash made it three RML Lacettis in the top four with an impressive performance, while Tom Onslow-Cole, back with the Arena Ford team for the first time since Croft, was a sensational -- and convincing -- fifth quickest.
Matt Neal was the quickest of the Vauxhall drivers in sixth, and also the best placed driver who did not improve his time in the afternoon session.
Harry Vaulkhard's Bamboo Engineering Chevrolet and Tom Chilton's Arena Ford were next up, while defending champion Fabrizio Giovanardi (Vauxhall) and David Pinkney (Dynamics Honda) completed the top 10.
Series debutant Johnny Herbert was under a tenth of a second slower than his team-mate Pinkney, while Anthony Reid, breaking a five-year BTCC layoff, spun into the gravel at Brooklands in the second session, and was 16th quickest.
Brooklands also created problems for Andrew Jordan, who spun in the morning session and damaged his Vauxhall's radiator. He was a disappointing 17th quickest, albeit only 1.3s off the pace.
Pos Driver Car Time
1. Jason Plato Chevrolet 1m00.625s
2. Mat Jackson Chevrolet 1m00.754s
3. Colin Turkington BMW 1m01.061s
4. James Nash Chevrolet 1m01.064s
5. Tom Onslow-Cole Ford 1m01.087s
6. Tom Chilton Ford 1m01.322s
7. Matt Neal Vauxhall 1m01.325s
8. Harry Vaulkhard Chevrolet 1m01.329s
9. Fabrizio Giovanardi Vauxhall 1m01.364s
10. David Pinkney Honda 1m01.378s
11. Johnny Herbert Honda 1m01.464s
12. Rob Collard BMW 1m01.465s
13. Paul O'Neill Honda 1m01.534s
14. Jonathan Adam BMW 1m01.528s
15. Stephen Jelley BMW 1m01.679s
16. Anthony Reid BMW 1m01.689s
17. Andrew Jordan Vauxhall 1m01.901s
18. Martyn Bell Honda 1m02.207s
19. John George Honda 1m02.485s
20. Martin Johnson Vauxhall 1m02.679s