Mattias Ekstrom led an Audi 1-2-3 in free practice ahead of this weekend's DTM finale at Hockenheim.
The two-time champion set a blistering lap time in the final minute of the session, as several drivers went out to do qualifying runs at the end. His Abt Sportsline team-mates Martin Tomczyk and Timo Scheider also showed good pace, locking out the top three places for Audi.
While Mercedes and Audi had been trading blows at the top of the timesheets throughout the session, by the end there was a distinct gap between Ekstrom and the top 2009-spec Mercedes of Gary Paffett, who could only manage seventh place with his final run.
Mercedes did appear to put less emphasis on any quick runs at the end of practice though, and Paffett was the only HWA driver to finish the session in the top 10.
Before the lead Audis set their best times in the closing stages, the session had been close as track conditions improved throughout after a damp start to the day.
A dry line only properly appeared with around an hour of the two and a half-hour session remaining, which left teams with little time to perfect their dry setups ahead of qualifying.
Ekstrom and Tomczyk fell down the order while they sat in the pits as the track improved through the final hour, but both shot straight back to the top with their first flying laps when they re-appeared with 20 minutes to go, firing an ominous warning shot to Mercedes.
There was an intriguing moment involving title contenders Scheider and Paffett as well during the earlier part of the session, when the pair ran on track together for a couple of laps with the Mercedes ahead.
Scheider then attempted to pass Paffett into the hairpin, but the 2005 champion contested the corner, leaving his braking late enough to keep the Audi at bay before letting him through before the next right-hander.
Pos Driver Car Time Gap
1. Mattias Ekstrom Audi 1m32.822s
2. Martin Tomczyk Audi 1m33.079s + 0.257s
3. Timo Scheider Audi 1m33.118s + 0.296s
4. Maro Engel Mercedes 1m33.355s + 0.533s
5. Jamie Green Mercedes 1m33.433s + 0.611s
6. Tom Kristensen Audi 1m33.483s + 0.661s
7. Gary Paffett Mercedes 1m33.690s + 0.868s
8. Mike Rockenfeller Audi 1m33.691s + 0.869s
9. Markus Winkelhock Audi 1m33.850s + 1.028s
10. Oliver Jarvis Audi 1m33.858s + 1.036s
11. Alexandre Premat Audi 1m33.877s + 1.055s
12. Ralf Schumacher Mercedes 1m34.015s + 1.193s
13. Katherine Legge Audi 1m34.115s + 1.293s
14. Bruno Spengler Mercedes 1m34.162s + 1.340s
15. Susie Stoddart Mercedes 1m34.663s + 1.841s
16. Mathias Lauda Mercedes 1m35.052s + 2.230s
17. Paul Di Resta Mercedes 1m35.116s + 2.294s
18. Christian Bakkerud Audi 1m35.234s + 2.412s
19. Tomas Kostka Audi 1m35.475s + 2.653s
20. Johannes Seidlitz Audi 1m35.589s + 2.767s