Andrew Jordan once again topped a British Touring Car session by going fastest in free practice at Donington Park.
The works Honda Civics had set the pace in the morning session, with reigning champion Gordon Shedden just 0.008 seconds ahead of team-mate Matt Neal, chased by the two MGs and Jordan.
But the pace was faster in the afternoon. Plato posted a 1m10.542s early on to beat both Shedden's morning mark and the MG driver's own 2012 pole time.
Jordan's Eurotech-run Civic then matched Plato to the nearest thousandth of a second before Shedden moved back to the front with 1m10.353s.
That mark lasted until a flurry of quick laps in the closing minutes.
Jordan recorded a 1m10.175s, then a 1m10.046s as he took the flag to secure the top spot, while Plato's last charge netted second from Shedden.
Sam Tordoff narrowly outpaced MG team-mate Plato in the morning and also improved in the afternoon. His late run resulted in 1m10.361s to put him fourth overall, ahead of Neal, who set almost identical times in the two sessions.
Toyotas filled the next three spots, Speedworks driver Dave Newsham taking sixth, from Frank Wrathall (Dynojet) and Adam Morgan (Ciceley Racing).
Colin Turkington's morning time was good enough for ninth in WSR's new NGTC BMW, but Motorbase continued to struggle with its NGTC Ford Focuses, neither Mat Jackson or Aron Smith making it into the top 10 on combined session times.
Having set the S2000 pace in the morning, James Kaye improved later in AmD's VW Golf to end up 20th overall as fastest Jack Sears Trophy runner.
Pos Driver Team/Car Time Gap
1. Gordon Shedden Honda 1m10.595s
2. Matt Neal Honda 1m10.603s + 0.008s
3. Sam Tordoff MG 1m10.860s + 0.265s
4. Jason Plato MG 1m10.880s + 0.285s
5. Andrew Jordan Eurotech Honda 1m10.893s + 0.298s
6. Adam Morgan Ciceley Toyota 1m10.932s + 0.337s
7. Colin Turkington WSR BMW 1m10.933s + 0.338s
8. Aron Smith Motorbase Ford 1m10.982s + 0.387s
9. Frank Wrathall Dynojet Toyota 1m11.035s + 0.440s
10. Dave Newsham Speedworks Toyota 1m11.098s + 0.503s
11. Mat Jackson Motorbase Ford 1m11.434s + 0.839s
12. Jeff Smith Eurotech Honda 1m11.554s + 0.959s
13. Tom Onslow-Cole HARD VW 1m11.606s + 1.011s
14. Rob Collard WSR BMW 1m11.632s + 1.037s
15. Ollie Jackson Speedworks Toyota 1m11.646s + 1.051s
16. Will Bratt Austin Audi 1m12.039s + 1.444s
17. Jack Goff HARD Vauxhall 1m12.288s + 1.693s
18. James Kaye AmD VW* 1m12.349s + 1.754s
19. David Nye Welch Ford* 1m13.027s + 2.432s
20. Warren Scott BMR SEAT* 1m13.042s + 2.447s
21. Nick Foster WSR BMW 1m13.051s + 2.456s
22. Rob Austin Austin Audi 1m13.068s + 2.473s
23. Lea Wood Wood Vauxhall* 1m13.269s + 2.674s
24. Liam Griffin Motorbase Ford 1m13.297s + 2.702s
25. Daniel Welch Welch Proton 1m13.390s + 2.795s
26. James Cole HARD Vauxhall 1m15.897s + 5.302s
27. Joe Girling Finesse Chevrolet*
Pos Driver Team/Car Time Gap
1. Andrew Jordan Eurotech Honda 1m10.046s
2. Jason Plato MG 1m10.230s + 0.184s
3. Gordon Shedden Honda 1m10.353s + 0.307s
4. Sam Tordoff MG 1m10.361s + 0.315s
5. Matt Neal Honda 1m10.606s + 0.560s
6. Dave Newsham Speedworks Toyota 1m10.775s + 0.729s
7. Frank Wrathall Dynojet Toyota 1m10.919s + 0.873s
8. Adam Morgan Ciceley Toyota 1m10.956s + 0.910s
9. Jeff Smith Eurotech Honda 1m11.064s + 1.018s
10. Árón Smith Motorbase Ford 1m11.149s + 1.103s
11. Mat Jackson Motorbase Ford 1m11.280s + 1.234s
12. Colin Turkington WSR BMW 1m11.281s + 1.235s
13. Jack Goff HARD Vauxhall 1m11.425s + 1.379s
14. Daniel Welch Welch Proton 1m11.592s + 1.546s
15. Will Bratt Austin Audi 1m11.742s + 1.696s
16. Ollie Jackson Speedworks Toyota 1m11.781s + 1.735s
17. Tom Onslow-Cole HARD VW 1m11.937s + 1.891s
18. Rob Collard WSR BMW 1m11.984s + 1.938s
19. Rob Austin Austin Audi 1m12.127s + 2.081s
20. James Kaye AmD VW* 1m12.222s + 2.176s
21. Liam Griffin Motorbase Ford* 1m12.600s + 2.554s
22. David Nye Welch Ford* 1m12.680s + 2.634s
23. Nick Foster WSR BMW 1m12.700s + 2.654s
24. Lea Wood Wood Vauxhall* 1m13.097s + 3.051s
25. Joe Girling Finesse Chevrolet* 1m13.132s + 3.086s
26. James Cole HARD Vauxhall 1m13.813s + 3.767s
27. Warren Scott BMR SEAT* 1m14.091s + 4.045s