Jason Plato took his second win of the day in the second British Touring Car encounter at Snetterton after a great tussle with Colin Turkington.
Turkington's WSR BMW jumped poleman Plato at the start to lead into Riches, but the safety car was soon scrambled after Alain Menu's BMR Volkswagen Passat and the Ciceley Mercedes of Adam Morgan clashed, putting the VW in the wall.
At the restart, at the end of lap four, Plato applied pressure to the BMW, finally making a move down the inside at Montreal on lap nine of 15.
Turkington came back at the MG for a few laps, before falling back to take the runner-up spot 1.6 seconds down.
Gordon Shedden's works Honda Civic Tourer came through from seventh to complete the podium.
The 2012 champion rose to fifth during the dramatic opening lap, then overtook Morgan's A-class for fourth around the outside at Brundle.
Shedden then closed on team-mate Matt Neal, who did not fight when the number 52 estate went down the inside at Montreal.
Motorbase Ford Focus pair Mat Jackson and Fabrizio Giovanardi followed Morgan home. Giovanardi went from 13th to seventh on lap one and then held off the BMR Passat of Aron Smith for much of the race.
The second MG of Sam Tordoff did even better, climbing to ninth from the back of the grid, while Marc Hynes - on the soft Dunlop tyre - made it three MG6s in the top 10 by narrowly beating Jack Goff's VW.
Reigning champion Andrew Jordan, who started 16th after his recovery drive in race one, rose to 10th early on, but it was not to be a happy race.
Jordan got by Rob Collard on the run out of Oggies, but the WSR BMW struck back on the Bentley Straight. Goff made it three abreast and the trio ran out of room at Brundle.
Jordan was forced into a spin and fell to 22nd. He came back and grabbed a single point by outdragging Dave Newsham's AmD Ford Focus by 0.043s on the run to the line.
Results - 15 laps:
Pos Driver Team/Car Time/Gap
1. Jason Plato MG 33m00.807s
2. Colin Turkington WSR BMW +1.608s
3. Gordon Shedden Honda +6.506s
4. Matt Neal Honda +8.072s
5. Adam Morgan Ciceley Mercedes +9.353s
6. Mat Jackson Motorbase Ford +11.109s
7. Fabrizio Giovanardi Motorbase Ford +11.977s
8. Aron Smith BMR VW +14.334s
9. Sam Tordoff MG +18.072s
10. Marc Hynes MG +20.556s
11. Jack Goff BMR VW +20.831s
12. Martin Depper Eurotech Honda +22.120s
13. Rob Austin RAR Audi +26.130s
14. Nick Foster WSR BMW +26.343s
15. Andrew Jordan Eurotech Honda +26.680s
16. Dave Newsham AmD Ford +26.723s
17. Aiden Moffat Moffat Chevrolet +41.418s
18. Rob Collard WSR BMW +53.675s
19. Lea Wood Houseman Toyota +53.854s
20. James Cole UA Toyota +57.483s
21. Simon Belcher Handy Toyota +1m03.170s
22. Ollie Jackson Welch Proton +1m04.051s
23. Chris Stockton BTC Chevrolet +1m13.574s
24. Hunter Abbott RAR Audi -1 lap
25. Jack Clarke Motorbase Ford -2 laps
Glynn Geddie UA Toyota 11 laps
Dan Welch Welch Proton 6 laps
Warren Scott BMR VW 5 laps
Robb Holland Rotek Audi 5 laps
Tom Ingram Speedworks Toyota 2 laps
Alain Menu BMR VW 0 laps