Poleman Cassidy took the rolling start alone on the front row after Duval aquaplaned on the damp track during a sighting lap and hit the barriers, terminally damaging his Audi RS5 DTM.

The New Zealander then stretched his legs ahead of the Hondas of Naoki Yamamoto and Koudai Tsukakoshi, his advantage peaking at seven seconds before the pitstops.

Cassidy was among the last to pit, doing so on lap 19 of 34, and on his fresher rubber he was able to extend the gap ahead of his pursuers, before the Safety Car was deployed on lap 29 to retrieve Daiki Sasaki's stricken Impul Nissan GT-R.

But the TOM'S driver was just able to resist the pressure from the Real Racing NSX-GT of Tsukakoshi to take victory by a scant 0.433s.

Yamamoto - who is racing alone in the Kunimitsu Honda this weekend with Jenson Button absent, completed the podium five seconds behind Cassidy, having slipped behind Tsukakoshi during the first stint and failing to keep up with the lead duo after the restart.

SUPER GT champion Kenta Yamashita took fourth in the LeMans Lexus after passing Sho Tsuboi's Bandoh Lexus on the penultimate lap.

Audi driver Benoit Treluyer was the top DTM finisher in sixth after coming out on top in a thrilling last-lap battle.

Rene Rast had been the top DTM runner for much of the distance as Audi stablemate Mike Rockenfeller, the top representative on the grid for the German series after Duval's crash, rapidly slid down the order in the closing stages.

Rast took the restart in eighth but was passed by one-time SUPER GT champion Treluyer, who then found a way by Yuhi Sekiguchi in the second TOM'S Lexus.

Yuji Tachikawa (Cerumo Lexus) and Hideki Mutoh (Mugen Honda) completed the top 10 ahead of the best of the Nissan finishers, Frederic Makowiecki (B-Max Racing) in 11th.

Ronnie Quintarelli had run second behind Cassidy in the early laps but dropped to the lower reaches of the top 10 during the opening stint and finished 12th.

Kamui Kobayashi, racing a DTM car for the first time, was best of the BMW contingent in 14th.

Marco Wittmann was one of two drivers - the other being Tadasuke Makino (Nakajima Racing Honda) - to start on wet tyres, and finished a lapped 18th after an early stop to return to slicks left him a long way adrift of the pack.

Alex Zanardi was classified 21st and last after an engine issue left him 18 laps down.

Race results: