Morning rain had abated by the time the session began, meaning rapidly tumbling times in the opening stages, with Andrea Iannone, Loris Baz and Marc Marquez among the early leaders.

Avintia Ducati man Hector Barbera became the first to breach the 1m47s barrier when he set a 1m46.851s, which was the benchmark when the rain returned around 20 minutes into the session.

But the worsening conditions didn't stop Rossi from improving his times, as the Yamaha rider leapt up to third and then into the top spot on a 1m46.709s.

Further improvements were to come as the rain eased up again, and Rossi's time was soon beaten by Redding, who logged a 1m46.655s on his GP16 Ducati.

The British rider, a podium finisher in the wet at Assen last year, soon improved to a 1m46.491s to cement his place atop the timesheets, and finally ended the session with a best of 1m46.441s.

Rossi found further time on his final lap, setting a 1m46.672s to end up 0.231s shy of Redding.

Marquez was third on the best of the Hondas, 0.302s off the pace, followed by the second works Yamaha of Maverick Vinales, another 0.013s behind, and Johann Zarco's Tech 3 Yamaha.

Barbera's earlier time proved enough for sixth, ahead of Aprilia's Aleix Espargaro, top factory Ducati rider Jorge Lorenzo, Loris Baz - who crashed at Turn 3 late on the second Avintia bike - and Andrea Iannone for Suzuki.

Andrea Dovizioso ended up outside the top 10 on the second works GP17 Ducati, one spot behind first practice pacesetter Danilo Petrucci.

Cal Crutchlow was the only other rider to crash, the LCR Honda man tumbling at Turn 8 late in the session and ending up 15th, 0.968s off the pace.

The second Repsol Honda of Dani Pedrosa was slowest of all, a full 2.850s off the pace and fractionally behind Tito Rabat's Marc VDS machine.

But with no riders improving on their Friday times, Pedrosa still gets an automatic bye into Q2, while Espargaro, Lorenzo, Redding, Baz and Barbera will all have to contest Q1.

Third practice results:

Pos.	#	Rider	Bike	Time	Gap
1	45	Scott Redding	Ducati	1'46.441
2	46	Valentino Rossi	Yamaha	1'46.672	0.231
3	93	Marc Marquez	Honda	1'46.743	0.302
4	25	Maverick Viñales	Yamaha	1'46.756	0.315
5	5	Johann Zarco	Yamaha	1'46.794	0.353
6	8	Hector Barbera	Ducati	1'46.851	0.410
7	41	Aleix Espargaro	Aprilia	1'46.936	0.495
8	99	Jorge Lorenzo	Ducati	1'47.075	0.634
9	76	Loris Baz	Ducati	1'47.126	0.685
10	29	Andrea Iannone	Suzuki	1'47.295	0.854
11	9	Danilo Petrucci	Ducati	1'47.306	0.865
12	4	Andrea Dovizioso	Ducati	1'47.310	0.869
13	94	Jonas Folger	Yamaha	1'47.355	0.914
14	43	Jack Miller	Honda	1'47.394	0.953
15	35	Cal Crutchlow	Honda	1'47.409	0.968
16	22	Sam Lowes	Aprilia	1'47.657	1.216
17	42	Alex Rins	Suzuki	1'47.767	1.326
18	44	Pol Espargaro	KTM	1'47.774	1.333
19	17	Karel Abraham	Ducati	1'47.908	1.467
20	19	Alvaro Bautista	Ducati	1'48.194	1.753
21	38	Bradley Smith	KTM	1'49.235	2.794
22	53	Tito Rabat	Honda	1'49.284	2.843
23	26	Dani Pedrosa	Honda	1'49.291	2.850