The Suzuki rider's FP1 benchmark of 2m02.483s was quickly demolished, as Iannone posted a 2m02.312s just shy of the 10-minute mark - Vinales himself slotting into second with a 2m02.671s.

That was how the order remained for much of the session, although Jorge Lorenzo slotted his Yamaha into third with an effort of 2m02.743s at the halfway mark.

In the final five minutes, Brno winner Cal Crutchlow put the LCR Honda on top with a 2m02.046s, which the home favourite quickly followed up with a 2m01.917s - but this wasn't enough to stay quickest for more than a couple of moments, as Vinales improved to a 2m01.721s.

That briefly seemed to be enough for the Spaniard to complete a clean sweep of Friday's practice sessions, as factory Ducati man Iannone came within a tenth of the top spot just before the chequered flag fell.

He then posted a 2m01.421s on his final lap to grab the top spot by precisely 0.300s from Vinales, with Crutchlow the only other rider within half a second of Iannone.

Lorenzo was fourth quickest, 0.611s behind the man he replaces at Ducati next season, with points leader Marc Marquez 0.819s off the pace in fifth on the second best of the Hondas.

Valentino Rossi completed the top six on the second Yamaha, 0.841s behind compatriot Iannone, ahead of the second works Ducati of Andrea Dovizioso.

Aleix Espargaro (Suzuki), Dani Pedrosa (Honda) and Scott Redding (Pramac Ducati) rounded off the top 10 runners of an entirely incident-free session.

After propping up the timesheets during first practice, Alex Lowes improved to P19 for his second MotoGP session, 1.3s behind Tech 3 Yamaha teammate Pol Espargaro.

Cla	#	Driver	Bike	Time	Gap
1	29	Andrea Iannone	Ducati	2'01.421
2	25	Maverick Viñales	Suzuki	2'01.721	0.300
3	35	Cal Crutchlow	Honda	2'01.917	0.496
4	99	Jorge Lorenzo	Yamaha	2'02.032	0.611
5	93	Marc Marquez	Honda	2'02.240	0.819
6	46	Valentino Rossi	Yamaha	2'02.262	0.841
7	4	Andrea Dovizioso	Ducati	2'02.267	0.846
8	41	Aleix Espargaro	Suzuki	2'02.364	0.943
9	26	Dani Pedrosa	Honda	2'02.372	0.951
10	45	Scott Redding	Ducati	2'02.533	1.112
11	44	Pol Espargaro	Yamaha	2'02.573	1.152
12	8	Hector Barbera	Ducati	2'02.608	1.187
13	9	Danilo Petrucci	Ducati	2'02.985	1.564
14	50	Eugene Laverty	Ducati	2'03.118	1.697
15	76	Loris Baz	Ducati	2'03.370	1.949
16	68	Yonny Hernandez	Ducati	2'03.380	1.959
17	43	Jack Miller	Honda	2'03.631	2.210
18	6	Stefan Bradl	Aprilia	2'03.642	2.221
19	22	Alex Lowes	Yamaha	2'03.855	2.434
20	19	Alvaro Bautista	Aprilia	2'04.400	2.979
21	53	Tito Rabat	Honda	2'05.196	3.775