After winning his opening two races with Yamaha in Qatar and Argentina, Vinales has set his sights on becoming the first rider other than Marquez to win at the Circuit of the Americas.

Marquez led the way after the first block of running, with a 2m05.535s lap, with Honda stablemates Cal Crutchlow - before a crash at Turn 6 - and Dani Pedrosa having also spent time at the top.

The Spaniard was 0.574 seconds clear of Pedrosa until he was pipped by Vinales, who turned a 2m05.462s with 15 minutes to go.

That put Vinales 0.073s ahead of Marquez, and he then set a 2m04.923s the next time around to go 0.612s clear.

Marquez improved again before the session was out, but only by less than a tenth, and Vinales finished with an advantage of 0.577s.

Ducati had a quiet session until the final five minutes, when Andrea Dovizioso jumped up from 12th to third, and Jorge Lorenzo from 16th to sixth.

Vinales’ Yamaha teammate Valentino Rossi also climbed up the order from outside the top 10 in the closing stages, on soft tyres, and finished eighth.

Tech 3 Yamaha’s Johann Zarco was the best of the rookies in fourth, while Alvaro Bautista pipped Lorenzo after the chequered flag to take fifth on his 2016-model Aspar Ducati, the last of the riders within a second of Vinales.

Pedrosa wound up seventh ahead of Rossi, while Aprilia’s Aleix Espargaro and Pramac Ducati’s Danilo Petrucci completed the top 10 as LCR Honda rider Crutchlow slipped to 11th.

Andrea Iannone tried Suzuki’s winglet-replacement front fairing but finished the session down in 16th place, 1.901s off the pace, four spots ahead of rookie teammate Alex Rins.

Pol Espargaro was the best of the KTMs in 21st place, after saving a wild moment under braking at Turn 12 inside the final 10 minutes.

First practice results:

Pos.	#	Rider	Bike	Time	Gap
1	25	Maverick Viñales	Yamaha	2'04.923
2	93	Marc Marquez	Honda	2'05.500	0.577
3	4	Andrea Dovizioso	Ducati	2'05.604	0.681
4	5	Johann Zarco	Yamaha	2'05.790	0.867
5	19	Alvaro Bautista	Ducati	2'05.833	0.910
6	99	Jorge Lorenzo	Ducati	2'06.017	1.094
7	26	Dani Pedrosa	Honda	2'06.109	1.186
8	46	Valentino Rossi	Yamaha	2'06.292	1.369
9	41	Aleix Espargaro	Aprilia	2'06.411	1.488
10	9	Danilo Petrucci	Ducati	2'06.469	1.546
11	35	Cal Crutchlow	Honda	2'06.484	1.561
12	43	Jack Miller	Honda	2'06.515	1.592
13	45	Scott Redding	Ducati	2'06.646	1.723
14	94	Jonas Folger	Yamaha	2'06.692	1.769
15	8	Hector Barbera	Ducati	2'06.786	1.863
16	29	Andrea Iannone	Suzuki	2'06.824	1.901
17	53	Tito Rabat	Honda	2'06.894	1.971
18	76	Loris Baz	Ducati	2'07.127	2.204
19	17	Karel Abraham	Ducati	2'07.300	2.377
20	42	Alex Rins	Suzuki	2'08.006	3.083
21	44	Pol Espargaro	KTM	2'08.128	3.205
22	22	Sam Lowes	Aprilia	2'08.292	3.369
23	38	Bradley Smith	KTM	2'08.740	3.817