Dani Pedrosa defeated MotoGP title rival Jorge Lorenzo in a fantastic last-lap duel at Brno.
The pair spent the entire 22 laps separated by less than four tenths of a second, and then swapped positions four times on the final lap before Pedrosa finally pulled ahead through the final corner, closing to within 13 points of the championship lead.
Cal Crutchlow meanwhile ended his wait for a maiden podium in the series by finishing third, having announced a contract extension with Tech 3 on the Saturday of the Czech Grand Prix.
The Briton was not quite able to live with the pace of Lorenzo and Pedrosa, who stretched out into the distance - Lorenzo initially ahead until Pedrosa dived down the inside at the penultimate corner at mid-distance.
Lorenzo opted to tuck in behind Pedrosa until the final lap, when he attacked and stole ahead in the stadium complex. Down the back straight Pedrosa responded, but Lorenzo stuck with the outside line and once again forged ahead, only to run wide and compromise his line into the final turn, allowing Pedrosa to come back through and claim the win.
The dice was all the more significant in the championship after Casey Stoner's decision to leave Brno and return home for ankle surgery.
The battle behind was never as close, with Andrea Dovizioso trailing Tech 3 stablemate Crutchlow by around two seconds for much of the race.
He was nevertheless close enough to pounce if Crutchlow made an error in the final laps, but with none coming had to settle for fourth. Crutchlow's podium is the first for a Briton since Jeremy McWilliams finished third at Donington Park 12 years ago.
After his best qualifying performance of the season, there were early signs that Ducati's Valentino Rossi might feature in the podium fight when he passed Dovizioso and Ben Spies on the opening lap.
As the race progressed however his pace did the opposite, and he eventually fell to seventh behind the satellite Hondas of Stefan Bradl and Alvaro Bautista.
Spies meanwhile endured another torrid race. He fell back to 13th over the opening two laps with a slipping clutch, charged back to eighth when the problem eased but then crashed out in the stadium section with 14 laps to run.
Results - 22 laps:
Pos Rider Team/Bike Time/Gap
1. Dani Pedrosa Honda 42m51.570s
2. Jorge Lorenzo Yamaha + 0.178s
3. Cal Crutchlow Tech 3 Yamaha + 12.343s
4. Andrea Dovizioso Tech 3 Yamaha + 18.591s
5. Stefan Bradl LCR Honda + 25.582s
6. Alvaro Bautista Gresini Honda + 29.451s
7. Valentino Rossi Ducati + 34.514s
8. Randy de Puniet Aspar Aprilia + 1m04.285s
9. Karel Abraham Cardion Ducati + 1m08.278s
10. Aleix Espargaro Aspar Aprilia + 1m09.972s
11. Toni Elias Pramac Ducati + 1m10.003s
12. Yonny Hernandez Avintia FTR-Kawasaki + 1m24.040s
13. Colin Edwards Forward Suter-BMW + 1m27.898s
14. Michele Pirro Gresini FTR-Honda + 1m36.165s
15. James Ellison Paul Bird Aprilia + 1m40.565s
16. Mattia Pasini Speed Master Aprilia + 1m41.226s
17. Danilo Petrucci Ioda-Aprilia + 1 Lap
Ivan Silva Avintia FTR-Kawasaki 9 laps
Ben Spies Yamaha 8 laps