Dani Pedrosa moved to the top of the timesheets during a wet final practice session for the Aragon MotoGP.
The MotoGP riders will head into qualifying without any dry laps after poor weather continued in Spain, although - unlike on Friday morning - there was enough moisture for sustained wet tyre running.
However conditions became more complicated in the closing stages, with a dry line developing on parts of the track.
Pedrosa, who celebrates his 27th birthday today, set the best time of the session on his 13th of 17 laps.
The Repsol Honda star's 2m 0.490s was 0.134s ahead of world championship leader Jorge Lorenzo, who starts this weekend 38 points ahead of Pedrosa.
Lorenzo's Yamaha team-mate Ben Spies was third fastest this morning, 0.222s from Pedrosa, as the Texan's 2m 0.219s Friday afternoon time remained unbeaten.
Monster Yamaha Tech 3's Andrea Dovizioso
led the satellite challenge in fourth (+0.237s) with Honda LCR's Stefan Bradl a fraction behind.
Sixth and seventh went to Cal Crutchlow and Karel Abraham, the fastest Ducati rider, who both fell during the session.
Abraham slid off his Cardion AB Ducati at low speed early on, with Crutchlow lowsiding from his Tech 3 Yamaha with seven minutes remaining.
The Englishman was unharmed, but his M1 dug into the mud and flipped, ruling him out of the closing stages.
Valentino Rossi took eighth for the factory Ducati team, 1.223s from Pedrosa. Repsol Honda stand-in Jonathan Rea was ninth with Rossi's team-mate Nicky Hayden
completing a top ten covered by 1.633s.
Gresini's Alvaro Bautista was over two-seconds from the top in eleventh, with fellow Spaniard Aleix Espargaro heading the CRT challenge in twelfth for Aspar.
Hector Barbera, who collided with Pedrosa last time at Misano, continues to look uncomfortable and was only 19th quickest for Pramac Ducati.Saturday practice:
1. Dani Pedrosa
2. Jorge Lorenzo
3. Ben Spies
4. Andrea Dovizioso
5. Stefan Bradl
6. Cal Crutchlow
7. Karel Abraham
8. Valentino Rossi
9. Jonathan Rea
10. Nicky Hayden
11. Alvaro Bautista
12. Aleix Espargaro
13. Yonny Hernandez
14. James Ellison
15. Mattia Pasini
16. Colin Edwards
17. Danilo Petrucci
18. Randy De Puniet
19. Hector Barbera
20. Michele Pirro
21. David Salom