Valentino Rossi protege Bagnaia - who has already secured a MotoGP ride for 2019 with Pramac Ducati - led virtually throughout the 20-lap contest after grabbing the lead from poleman Alex Marquez at Turn 1 on the opening lap.

Bagnaia, Pons rider Baldassarri and Marc VDS man Marquez formed a lead trio that pulled away rapidly from the chasing pack, with Bagnaia able to keep his rivals at arm's length until the closing stages.

Marquez and Baldassarri swapped places several times in their fight for second before the former lost ground when his rear brake appeared to get stuck on during the 15th lap.

With Marquez out of the picture, Baldassarri soon closed on leader Bagnaia and began the final lap right on his compatriot's tail.

Baldassarri attempted a lunge at the Turn 15 left-hander, but couldn't make the move stick, conceding the lead to Bagnaia again and finishing up just 0.112s behind at the chequered flag.

Marquez held on for third place a further five seconds back after his brake problem, one second ahead of Italtrans rider Mattia Pasini.

The works KTMs of Miguel Oliveira and Brad Binder ended up fifth and sixth, the former recovering after running wide at the first corner and dropping to the lower fringes of the top 10.

Completing the top 10 were Intact GP duo Marcel Schrotter and Xavi Vierge, Bagnaia's VR46 teammate Luca Marini and the Gresini machine of Jorge Navarro.

Moto3 champion Joan Mir started his maiden Moto2 race down in 24th, but recovered to 11th place on board the second Marc VDS Kalex.

His former rival Romano Fenati went in the opposite direction, starting an impressive fifth but slumping to 24th by the chequered flag.

Hector Barbera was 13th on his Moto2 return on the second Pons bike, while fellow MotoGP refugee Sam Lowes crashed out while running inside the top 10 aboard the CGBM Evolution KTM.

Lowes and teammate Iker Lecuona, who suffered mechanical issues, were the only non-finishers.

Race results:

Pos.	#	Rider	Bike	Time/Gap
1	42	Francesco Bagnaia	Kalex	40'19.802
2	7	Lorenzo Baldassarri	Kalex	0.112
3	73	Alex Marquez	Kalex	5.625
4	54	Mattia Pasini	Kalex	6.657
5	44	Miguel Oliveira	KTM	10.296
6	41	Brad Binder	KTM	10.344
7	23	Marcel Schrötter	Kalex	11.419
8	97	Xavi Vierge	Kalex	11.516
9	10	Luca Marini	Kalex	20.690
10	9	Jorge Navarro	Kalex	20.961
11	36	Joan Mir	Kalex	23.025
12	87	Remy Gardner	Tech 3	30.292
13	40	Hector Barbera	Kalex	30.299
14	24	Simone Corsi	Kalex	30.732
15	77	Dominique Aegerter	KTM	30.870
16	32	Isaac Viñales	Kalex	31.052
17	52	Danny Kent	Speed Up	31.958
18	64	Bo Bendsneyder	Tech 3	32.382
19	5	Andrea Locatelli	Kalex	35.228
20	20	Fabio Quartararo	Speed Up	35.357
21	45	Tetsuta Nagashima	Kalex	35.969
22	4	Steven Odendaal	NTS	42.545
23	89	Khairul Idham Pawi	Kalex	42.776
24	13	Romano Fenati	Kalex	44.562
25	16	Joe Roberts	NTS	56.077
26	62	Stefano Manzi	Suter	1'01.581
27	95	Jules Danilo	Kalex	1'01.853
28	63	Zulfahmi Khairuddin	Kalex	1'11.618
29	21	Federico Fuligni	Kalex	1'20.148
30	51	Eric Granado	Suter	1'26.192
Ret	22	Sam Lowes	KTM	10 laps
Ret	27	Iker Lecuona	KTM	13 laps