Casey Stoner edged works Honda team-mate Dani Pedrosa in a tight first MotoGP practice session ahead of the Catalunya Grand Prix.
Pedrosa was the first rider to dip below the 1m43s mark, which was enough to keep him on top for the majority of the session. With seven minutes to go, however, Stoner captured the top spot with a two-lap salvo, shaving one tenth of a second off Pedrosa's benchmark.
Yamaha's Jorge Lorenzo moved into third in the final 30 seconds of the session, finishing just 0.233s down on Stoner.
Tech 3 Yamaha's Cal Crutchlow sealed fourth, although Ben Spies' Yamaha, LCR Honda's Stefan Bradl and the works Ducati of Nicky Hayden all finished within seven hundredths of a second of his time.
A close session was also reflected in the fact that Karel Abraham on the Cardion Ducati finished 0.540s down on Stoner in eighth, and also in the fact that Tech 3's Andrea Dovizioso, second fastest with 15 minutes to go, was bumped down to ninth at the finish.
Alvaro Bautista (Gresini Honda), Valentino Rossi (Ducati) and Hector Barbera (Pramac Ducati) rounded out the top 12, all three lapping within nine tenths of a second of Stoner.
Aspar's Randy de Puniet topped the CRT standings in 13th, while Forward's Colin Edwards, returning this weekend after injury forced him to miss Le Mans, was 17th.
Pos Rider Team Time Laps
1. Casey Stoner Repsol Honda Team 1m42.775s 16
2. Dani Pedrosa Repsol Honda Team 1m42.875s + 0.100 16
3. Jorge Lorenzo Yamaha Factory Racing 1m43.008s + 0.233 18
4. Cal Crutchlow Monster Yamaha Tech 3 1m43.182s + 0.407 19
5. Ben Spies Yamaha Factory Racing 1m43.191s + 0.416 20
6. Stefan Bradl LCR Honda MotoGP 1m43.245s + 0.470 17
7. Nicky Hayden Ducati Team 1m43.246s + 0.471 20
8. Karel Abraham Cardion AB Motoracing 1m43.315s + 0.540 20
9. Andrea Dovizioso Monster Yamaha Tech 3 1m43.371s + 0.596 20
10. Alvaro Bautista San Carlo Honda Gresini 1m43.493s + 0.718 19
11. Valentino Rossi Ducati Team 1m43.537s + 0.762 20
12. Hector Barbera Pramac Racing Team 1m43.624s + 0.849 17
13. Randy De Puniet Power Electronics Aspar 1m44.915s + 2.140 18
14. Aleix Espargaro Power Electronics Aspar 1m45.281s + 2.506 17
15. Michele Pirro San Carlo Honda Gresini 1m45.939s + 3.164 19
16. Mattia Pasini Speed Master 1m46.234s + 3.459 17
17. Colin Edwards NGM Mobile Forward Racing 1m46.748s + 3.973 13
18. Ivan Silva Avintia Blusens 1m46.848s + 4.073 14
19. James Ellison Paul Bird Motorsport 1m46.908s + 4.133 19
20. Danilo Petrucci Came IodaRacing Project 1m47.149s + 4.374 15
21. Yonny Hernandez Avintia Blusens 1m47.181s + 4.406 14