Andrea Dovizioso was quickest in MotoGP FP1 for the San Marino Grand Prix, while Marc Marquez and Valentino Rossi dropped out of the top 10 in 13th and 15th respectively.
The first MotoGP action since the cancelled British Grand Prix got underway in dry conditions at Misano, with Dovizioso ending the morning fastest of all on his Ducati with a 1:32.608s set in the closing stages.
In the opening minutes of the session, Honda's Marc Marquez and Maverick Vinales on the Yamaha traded top spot, with the former usurping Vinales' 1:34.963s with a 1:34.695s.
LCR's Cal Crutchlow demoted his Honda stablemate by just a few hundredths, before the Ducati duo made their assault on the top of the timesheets.
Jorge Lorenzo – who tested at Misano last month along with teammate Dovizioso, Yamaha and Aprilia – went top first with a 1:34.602s, before Dovizioso streaked clear with a 1:33.702s.
Vinales returned to top spot with a 1:33.575s, with Marquez once again pushing him back by just over a tenth with 22 minutes remaining.
With rain threatening this afternoon's FP2 and running on Saturday, a flurry of fast laps came in the closing minutes from the field in a bid to secure a provisional Q2 place.
Marquez and Rossi did not switch to fresh tyres for a time attack and suffered the consequences, with the former slipping to 13th while Rossi could only must 15th.
Lorenzo was the first big improver with a 1:32.807s, which put him 0.6s clear of the field briefly, before Dovizioso edged ahead with a 1:32.690s.
The Italian would improved to a 1:32.608s, which remained unchallenged as the chequered flag brought the session to a close, with Crutchlow leaping up to second a tenth adrift.
Vinales completed the top three from Lorenzo and Suzuki's Andrea Iannone, while Jack Miller held onto sixth despite a later fall at Turn 1.
A final effort of 1:33.209s lifted Dani Pedrosa up to seventh, with the top 10 rounded out by Johann Zarco, Danilo Petrucci and Franco Morbidelli.
Pol Espargaro made his return to action in FP1 having been absent since the Brno race with injury, and was 21st with a 1:34.614s lap on a KTM fitted with a new aerodynamic fairing.
A tenth ahead in 20th came HRC wildcard Stefan Bradl, making his third appearance this year, while Ducati wildcard Michele Pirro was almost a second in front in 16th.
Avintia's Xavier Simeon was 23rd with a 1:34.967s in his first session on the GP17, while Tito Rabat's stand-in Christophe Ponnson was last of the 26-strong field on his MotoGP debut and outside the required 107 percent of the fastest laptime.
