Nicky Hayden provided the Factory Ducati team with a welcome morale boost by topping the timesheets on day two of the Jerez MotoGP test.
The American, sixth and 1.4sec behind Honda's Casey Stoner on the opening day, jumped to the head of the field during a frantic flurry of late lap times on a drying track.
The 2006 world champion's best time of 1m 40.755s was 1.6sec off Stoner's Friday best, but only 0.25sec from Hayden's own day one mark.
A lesser known rider led the timesheets for most of the second day. Avintia's MotoGP rookie Ivan Silva was one of only two riders to get some dry laps in before the wind and rain arrived. The other was Ducati test rider Franco Battaini.
The track then fell silent as riders waited in vain for better weather, before most opted to do some wet running at around 2pm. Stoner's Repsol team-mate Dani Pedrosa was quickest in the wet, but had already packed up by the time the track finally returned to slick-tyre conditions late in the day.
Five riders were able to move ahead of Silva in the closing minutes, but Hayden was a full 0.9sec clear of second placed Karel Abraham (Cardion AB Ducati). Factory Yamaha's Ben Spies, Gresini Honda's Alvaro Bautista and Pramac Ducati's Hector Barbera completed the top five ahead of Silva's FTR-Kawasaki CRT machine.
Former grand prix rider Battaini was credited with seventh, while Michele Pirro (Gresini FTR-Honda), James Ellison (PBM ART) and Danilo Petrucci (Ioda-Aprilia) completed the top ten.
Suter-BMW rider Colin Edwards made it four CRTs in a row, with Pedrosa's wet time good enough for twelfth out of the 21 riders to complete a lap
Fellow Spaniard Jorge Lorenzo (Factory Yamaha) was one place behind, having also opted against a late run, with reigning double world champion Stoner 18th after completing just three wet laps.
The Australian was followed on the timesheets by Valentino Rossi, usually competitive in the wet on the Desmosedici, but just 19th fastest from his 18 laps on Saturday. Rossi, still seeking a better front-end feeling on his Desmosedici, will be hoping more than most for a dry final day of testing on Sunday.