Mercedes' Christian Vietoris came from the back of the field to take an incredible maiden DTM win in wet conditions at Oschersleben.
With light rain beginning to fall on the formation lap, the HWA driver rolled the dice, he and Daniel Juncadella coming in to switch to wet tyres while the rest of the field took the start.
When it started to rain heavier after several laps, the strategy began to pay off, particularly for Vietoris, who then got a further break in the form of two early safety car periods.
On lap 18 Vietoris and HWA made their second smart strategic call of the day, making a second stop to clear the obligatory 'window' pitstop, which must happen in the second third of the race, earlier than everyone else.
Once again the safety car helped out, Vietoris immediately closing the gap to the field, and then streaking into the lead when the frontrunners all had to make their pit window stop late in the race.
Mike Rockenfeller was second - just 0.6 seconds behind Vietoris at the end - having used a very similar strategy to the winner.
While the Audi driver did not switch to wets until lap seven, he did mimic Vietoris' early second stop, helping him to a surprising second place ahead of Edoardo Mortara, who recovered from being spun early by Pascal Wehrlein to finish third.
The biggest escape of the day went to Paul di Resta. The Scot finished a fine fourth, despite being tipped off the road at speed by Maxime Martin on lap 13.
Again, the key was making that second crucial stop before the third safety car period, di Resta stopping on lap 23.
Augusto Farfus finished fifth, Miguel Molina sixth, Timo Scheider seventh and Gary Paffett made it three Mercedes in the points with eighth.
Martin Tomczyk and Adrien Tambay rounded out the points-paying positions.
Results - 44 laps:
Pos Driver Team/Car Time/Gap
1. Christian Vietoris HWA Mercedes 1h15m28.785s
2. Mike Rockenfeller Phoenix Audi +0.674s
3. Edoardo Mortara Abt Audi +7.769s
4. Paul di Resta HWA Mercedes +8.906s
5. Augusto Farfus RBM BMW +9.326s
6. Miguel Molina Abt Audi +13.051s
7. Timo Scheider Phoenix Audi +20.503s
8. Gary Paffett HWA Mercedes +20.597s
9. Martin Tomczyk Schnitzer BMW +23.079s
10. Adrien Tambay Abt Audi +24.340s
11. Antonio Felix da Costa MTEK BMW +24.620s
12. Bruno Spengler Schnitzer BMW +26.892s
13. Mattias Ekstrom Abt Audi +27.201s
14. Maxime Martin RMG BMW +31.032s
15. Joey Hand RBM BMW +39.802s
16. Nico Muller Rosberg Audi +44.324s
17. Vitaly Petrov Mucke Mercedes +55.493s
18. Jamie Green Rosberg Audi -1 lap*
19. Marco Wittmann RMG BMW -1 lap
* Not running at finish
Pascal Wehrlein HWA Mercedes 26 laps
Daniel Juncadella Mucke Mercedes 22 laps
Timo Glock MTEK BMW 13 laps
Robert Wickens HWA Mercedes 9 laps