Andrea Dovizioso posted an unofficial lap record to lead the second MotoGP practice times on Friday at Le Mans ahead of championship leader Marc Marquez.
Ahead of FP2, Ducati confirmed Dovizioso would be remaining with the Italian manufacturer through to the end of 2020 after agreeing a new two-year deal.
It was team-mate Jorge Lorenzo who was the early pacesetter in FP2, the Spaniard – who is running a revised GP18 chassis this weekend – going top with a 1:34.720s.
Home hero Johann Zarco took over from the Ducati rider just moments later with a 1:33.158s, before FP1 pacesetter Marquez took over at the top of the timesheets by four tenths with a 1:32.581s.
Honda stablemate Cal Crutchlow briefly usurped him with a 1:32.586s, but Marquez responded to retake top spot by just 0.005 seconds.
Marquez further improved to a 1:32.318s with 15 minutes to go, which stood until the final three minutes, when Zarco reclaimed first place with a 1:32.279s.
Dovizioso denied the French crowd the chance to celebrate, as he dipped underneath the existing lap record with a 1:31.971s, before bettering that on his final attempt to a 1:31.936s.
Marquez leaped back up to second on his final lap on a used hard tyre, with Yamaha's Valentino Rossi heading team-mate and last year's French Grand Prix winner Maverick Vinales in third spot.
Zarco ended the opening day of his home round fifth on the Tech3 Yamaha, with Jack Miller close behind on his Pramac Ducati GP17.
Pol Espargaro recovered from a fall at Musee corner early in the session to put his KTM provisionally into Q2 in seventh, with Dani Pedrosa, Aleix Espargaro and Lorenzo rounding out the top 10.
A late crash for Crutchlow saw him shuffled outside of the top 10 into 11th, with Pramac's Danilo Petrucci unable to improve on 13th after a crash at La Chapelle with 20 minutes of the session remaining.
Scott Redding [21st], Franco Morbidelli [20th] and Takaaki Nakagami [17th] also fell foul of the hotter conditions at Le Mans in FP2 and crashed.
