Hector Barbera, Alex Debon and Alvaro Bautista got the last-ever 250cc race weekend off to a good start by locking out the top three positions on home ground at Valencia.
The trio rarely featured outside the top five as they disputed honours around the Comunitat Ricardo Tormo circuit, Barbera eventually getting the nod over Debon with a lap time of 1min 36.185secs.
Aprilia counterparts – and countrymen – Debon and Bautista followed three and sixth tenths adrift respectively, just ahead of champion-elect Hiroshi Aoyama.
Needing just five points – or eleventh position – to ensure the final 250cc title goes his and Honda's way, Aoyama crept up to fourth late in the session having spent much of the hour focusing on race set-up.
The only man that can beat him to the title, Marco Simoncelli, was two tenths slower in sixth position, the pair being split by Aoyama's Scot team-mate Raffaele de Rosa.
Hector Faubel, Mike di Meglio, Ratthapark Wilairot and Thomas Luthi completed the top ten, the latter having experienced a trip across the gravel early on in the session.
Friday practice - Valencia:
1. Barbera (Aprilia) 1min 36.185secs
2. Debon (Aprilia) +0.317sec
3. Bautista (Aprilia) +0.681sec
4. H. Aoyama (Honda) +0.739sec
5. de Rosa (Honda) +0.914sec
6. Simoncelli (Gilera) +0.980sec
7. Faubel (Honda) +1.028sec
8. di Meglio (Aprilia) +1.088sec
9. Wilairot (Honda) +1.241sec
10. Luthi (Aprilia) +1.621sec
24. Dunlop (Honda) +9.901sec