Maverick Vinales led the way for Suzuki in first practice for MotoGP's Catalunya Grand Prix at Barcelona.
Jorge Lorenzo was on top for the bulk of the 45 minutes on the Yamaha Vinales will take over next season, with a time of 1m42.143s.
With five minutes remaining, that lap had Lorenzo the best part of half a second clear of the field, until Vinales set what would become the benchmark.
Vinales' 1m42.065s was ultimately 0.078 seconds clear at the top.
Valentino Rossi was third on his Yamaha, 0.471s behind Vinales, while KTM-bound Pol Espargaro was fourth and the top satellite rider for Tech3 Yamaha, ahead of Yonny Hernandez.
Espargaro and Aspar Ducati's Hernandez jumped up from 12th and 11th respectively in the final minutes.
Those efforts shuffled Ducati's Andrea Iannone and Honda's Marc Marquez down to sixth and seventh.
Hector Barbera also improved late and wound up eighth, despite crashing at Turn 2 on his outlap, just seconds into the session.
Marc VDS pair Jack Miller and Tito Rabat - less than a fortnight after fracturing his collarbone at Mugello - also crashed at Turn 2, Miller halfway through the session and Rabat in the closing stages, and wound up 18th and 21st.
Cal Crutchlow was in the top five for the bulk of the morning on his LCR Honda but ultimately shuffled back to ninth, while Vinales' Suzuki team-mate Aleix Espargaro completed the top 10.
A little more than one second behind Vinales, Alvaro Bautista was a promising 11th for Aprilia, while Andrea Dovizioso and Dani Pedrosa had to settle for 13th and 14th.
|4||Pol Espargaro||Tech3 Yamaha||0.644s||16|
|5||Yonny Hernandez||Aspar Ducati||0.702s||17|
|8||Hector Barbera||Avintia Ducati||0.861s||14|
|9||Cal Crutchlow||LCR Honda||0.929s||18|
|12||Scott Redding||Pramac Ducati||1.137s||14|
|15||Eugene Laverty||Aspar Ducati||1.257s||18|
|16||Bradley Smith||Tech3 Yamaha||1.405s||20|
|17||Danilo Petrucci||Pramac Ducati||1.718s||15|
|18||Jack Miller||Marc VDS Honda||1.760s||16|
|20||Michele Pirro||Avintia Ducati||2.197s||16|
|21||Tito Rabat||Marc VDS Honda||3.057s||18|