Casey Stoner took over at the top during Friday's second practice session for the Portuguese MotoGP at Estoril.

Following this morning's damp session, led by Ben Spies, the afternoon track conditions were more consistent - despite strong winds - prompting all 21-riders to take to the track (Jorge Lorenzo and Hector Barbera having sat out the morning session).

Spies picked up where he left off, soon beating his best morning time, before world champion Stoner moved ahead at the halfway stage of the 45-minutes. Cal Crutchlow then bumped Spies down to third, before the Englishman was himself displaced by Lorenzo.

Spies briefly reclaimed the top spot from Stoner, but the Australian - chasing his first Estoril MotoGP victory on Sunday - fixed his Repsol Honda permanently into P1 with a time of 1m 38.396s (1.5s off the lap record) on his 13th of 16 laps.

Spies, determined to bounce back after starting the season with a pair of eleventh places, confirmed second place (+0.321s) albeit with satellite Tech 3 Yamaha rider Cal Crutchlow and last year's Estoril winner Dani Pedrosa both within 0.055s of the Texan's factory M1.

After missing the morning Lorenzo - who has qualified on pole for all four of his premier-class appearances at Estoril, winning between 2008 and 2010, then finishing second last year - collected a close fifth position (+0.524s).

San Carlo Honda Gresini rider Alvaro Bautista made a strong start with sixth place (+0.563s), while Nicky Hayden - second in the damp FP1 - led a trio of Ducatis in seventh, eighth (Hector Barbera) and ninth (Valentino Rossi).

Competitive in the damp, the top Ducatis spent much of the session towards the lower end of the top ten. Rossi was the final rider within one-second of Stoner.

Fellow Italian Andrea Dovizioso was tenth for Tech 3, with Karel Abraham (Ducati) and rookie Stefan Bradl (Honda) the last of the manufacturer bikes.

Randy de Puniet, cruelly denied twelfth and top CRT after fuel supply problems in the closing laps at Jerez, returned to the head of the privateer field in 13th place, 2.7s from Stoner but only 0.19s from Bradl.

De Puniet's Aspar team-mate Aleix Espargaro was half a second slower, followed by Yonny Hernandez, who delivered another solid performance on Avintia's FTR-Kawasaki.

Suter BMW's Colin Edwards was 18th, with PBM's James Ellison rounding out the 21-rider field.

Friday practice (2):

1. Casey Stoner
2. Ben Spies
3. Cal Crutchlow
4. Dani Pedrosa
5. Jorge Lorenzo
6. Alvaro Bautista
7. Nicky Hayden
8. Hector Barbera
9. Valentino Rossi
10. Andrea Dovizioso
11. Karel Abraham
12. Stefan Bradl
13. Randy De Puniet
14. Aleix Espargaro
15. Yonny Hernandez
16. Mattia Pasini
17. Michele Pirro
18. Colin Edwards
19. Ivan Silva
20. Danilo Petrucci
21. James Ellison