Andrea Iannone beat Marc Marquez by 0.390 seconds to top first MotoGP practice ahead of the German Grand Prix.
Maverick Vinales set the very early pace in the opening 45-minute session of the weekend with a 1:23.936s, though the Yamaha man was quickly usurped by Sachsenring specialist Marquez with a 1:22.354s.
Marquez – who has won for the last eight years at the German venue – lowered his benchmark to a 1:21.984s on his follow-up tour, before eding a tenth quicker with a 1:21.832s.
Initially six tenths clear of the field, the rest chipped away at the Spaniard's time across the opening half of the session, with Suzuki's Iannone his closest challenger, 0.288s adrift.
Iannone put the Spaniard's place at the top of the timesheets under threat as the session entered its final 10 minutes, the Suzuki rider closing his deficit down to just 0.054s.
With eight minutes remaining, Iannone demoted Marquez from top spot with a 1:21.442s, whi ch moved him almost four tenths clear of the rest.
Iannone remained unchallenged to through the chequered flag, with Marquez settling for second in the end with his early effort of 1:21.832s.
Valentino Rossi headed Yamaha teammate Vinales in third, just over a tenth down on Marquez's time, while Andrea Dovizioso lead a Ducati quartet in fifth spot.
Danilo Petrucci edged ahead of Pramac stablemate Jack Miller with a 1:22.337s in sixth, while Jorge Lorenzo found himself just 0.007s outside of Miller's best in eighth.
Scott Redding's racing future remains unclear as he enters the halfway stage of the season, and was ninth on the Aprilia ahead of Tech Yamaha's Johann Zarco.
12th-placed Alex Rins was one of three fallers in the session, the Suzuki rider going down at the Omega curve just seconds before Tito Rabat [16th] and Alvaro Bautista [13th] threw their customer Avintia and Nieto Ducatis at the scenery of the Sachsen Kurve and the Coca-Cola Kurve.
The retiring Dani Pedrosa, who announced on Thursday he would be stepping away from the sport at the end of the year, made a low-key start to his German Grand Prix weekend in 14th, 1.2s off the pace of Iannone.
Honda stablemate Cal Crutchlow was similarly quiet in FP1, the LCR rider only 19th on the third of the factory RC213Vs.
Mika Kallio makes his third appearance of the season this weekend for KTM, and was 24th-fastest in FP1, with only Avintia's Xavier Simeon behind him.