Superstar rookie Marc Marquez moved to the top of the timesheets during Saturday morning practice for his home Catalunya MotoGP.
The Moto2 champion, sixth on Friday, moved ahead in the closing stages of FP3, building an advantage of 0.134s over Repsol Honda team-mate Dani Pedrosa during two successive fast laps.
However Nicky Hayden then shot into second for Ducati, with a best time just 0.063s from Marquez.
Behind title leader Pedrosa, Friday pace setter Valentino Rossi, Monster Yamaha Tech 3's Cal Crutchlow and reigning world champion Jorge Lorenzo completed a top six covered by just 0.3s!
The softer rear tyre was the favoured choice this morning, combined with the harder front, although Lorenzo returned on the soft front after suffering an early fall.
Lorenzo lost the front of his M1 at the apex of turn five and slid into the gravel. Forced to abandon his machine - after rushing to switch off the engine - Lorenzo returned to the pits by scooter before re-joining the session on his spare bike.
Stefan Bradl (LCR Honda), Andrea Dovizioso (Ducati), Alvaro Bautista (Gresini Honda) and Aleix Espargaro (Aspar) completed the morning top ten. Top CRT rider Espargaro was as high as seventh in the closing stages and set a best lap under one-second from countryman Marquez.
All riders set their best times of the weekend this morning.
The top ten after FP3 (on combined times) receive direct access to the second and final part of this afternoon's qualifying session.
The manufacturer riders' missing out were injured rookie Bradley Smith (Tech 3 Yamaha), Pramac Ducati stand-in Michele Pirro - riding the 'lab' version of the Desmosedici, in place of Ben Spies - and team-mate Andrea Iannone, who were eleventh, twelfth and 13th respectively.
Joining Lorenzo in the gravel this morning were PBM's Yonny Hernandez and Avintia's Hiroshi Aoyama.
Free practice four will be held just before the start of this afternoon's pair of qualifying sessions.
Free practice 3:
1. Marc Marquez
2. Nicky Hayden
3. Dani Pedrosa
4. Valentino Rossi
5. Cal Crutchlow
6. Jorge Lorenzo
7. Stefan Bradl
8. Andrea Dovizioso
9. Alvaro Bautista
10. Aleix Espargaro
11. Bradley Smith
12. Michele Pirro
13. Andrea Iannone
14. Randy De Puniet
15. Hector Barbera
16. Colin Edwards
17. Danilo Petrucci
18. Karel Abraham
19. Michael Laverty
20. Claudio Corti
21. Hiroshi Aoyama
22. Yonny Hernandez
23. Bryan Staring
24. Lukas Pesek
Don't miss out! The next round of the 2013 MotoGP World Championship takes place at Assen on June 27-29 - CLICK HERE for tickets from the Official MotoGP Ticket Store.