Wittmann headed home stablemates Tom Blomqvist and Bruno Spengler, the latter picking up a podium spot when erstwhile championship leader Robert Wickens slowed with a car issue.

Off the line, Wickens, who had inherited P3 after Maxime Martin's exclusion from qualifying, unsuccessfully tried to challenge Blomqvist for runner-up - but the BMW man held position as Wittmann stormed off up ahead.

From that point on, Blomqvist focused on keeping Wickens behind, Wittmann's lead growing to 7.1s by the end of the opening stint.

Having built a safe gap, the 2014 champion was the first driver to make a mandatory stop, doing so on lap 13.

Blomqvist and Wickens stayed out for a few more tours, the Canadian visiting the pits on lap 19 and enduring a slow tyre change.

Covering off for Wickens a lap later, Blomqvist rejoined significantly closer to Wittmann, the latter having run a few laps in traffic.

The gap between the two stabilised at between three and four seconds from that point on and Wittmann duly saw out the race distance for his second victory of the season.

Meanwhile, having already dropped ground, Wickens began to severely struggle for pace, reporting that the car was "undriveable".

Soon, he had Spengler all over him, the BMW man having rejoined between Wickens and another Mercedes driver Dani Juncadella.

On lap 30, Spengler passed Wickens at Turn 2 and stormed off into the distance to complete an all-BMW podium.

Wickens, radioing in that he had "no more steering", now had a train of cars behind him and, despite Juncadella acting as rear gunner, both were shortly passed by Augusto Farfus for P4.

However, nursing a clearly ailing car home, Wickens did hold on to fifth, just keeping Edoardo Mortara at bay over the line, the Italian having run a spectacular race from P18 on the grid.

Juncadella was not so lucky, dropping out of the points in the very final corner, as Nico Muller, Adrien Tambay, Mattias Ekstrom and Lucas Auer made up the top 10.

It was a busy race for the stewards, and two championship contenders in particular fell foul of the rulebook.

Jamie Green, making progress from P20 on the grid, received a drive-through penalty for tapping Antonio Felix da Costa into a spin in the final corner at Turn 12 - and was then penalised again for failing to maintain the pitlane speed limit.

A similar fate befell Paul di Resta, who was running in the points when he nudged Timo Glock into a spin, picking up a drive-through penalty and subsequently getting summoned to the stewards for failing to correctly maintain the Slow Zone.