Mattias Ekstrom put Audi on top in the final free practice session for this weekend's DTM finale at Hockenheim on Saturday morning.
The Abt Sportsline driver, who was on pole for the first race of 2012 at the same circuit, set the pace in 1m33.802s, his lap coming right at the end of the 90-minute session.
Ekstrom's lap, which was faster than even the F3 Euro Series runners went on Friday qualifying, was 0.130s up on the Phoenix-run A5 of Mike Rockenfeller.
Rosberg's Edoardo Mortara ensured that each of Audi's teams was represented in the top three with the third fastest time, while Dirk Werner was BMW's best-placed driver in fourth for Schnitzer Motorsport.
Timo Scheider (Abt) and Augusto Farfus (RBM BMW) were ahead of championship leader Gary Paffett, who was the best-placed Mercedes driver in seventh.
Martin Tomczyk, whose tenure as DTM champion will come to an end tomorrow, was eighth, with Adrien Tambay the meat in an RMG BMW sandwich as Joey Hand completed the top 10.
Bruno Spengler and Jamie Green, the two drivers that can deny Paffett the championship this weekend, were 12th and 14th fastest respectively.
Roberto Merhi's session began eventfully as a right-rear wheel detached itself from his Persson Mercedes shortly after he left the pits.
Miguel Molina also had a moment later on as he slid into the gravel at the Sachs Kurve, his Phoenix Audi coming to rest against the tyre wall.
Pos Driver Team/Car Time Gap
1. Mattias Ekstrom Abt Audi 1m33.802s
2. Mike Rockenfeller Phoenix Audi 1m33.932s + 0.130s
3. Edoardo Mortara Rosberg Audi 1m33.953s + 0.151s
4. Dirk Werner Schnitzer BMW 1m34.035s + 0.233s
5. Timo Scheider Abt Audi 1m34.077s + 0.275s
6. Augusto Farfus RBM BMW 1m34.105s + 0.303s
7. Gary Paffett HWA Mercedes 1m34.120s + 0.318s
8. Martin Tomczyk RMG BMW 1m34.169s + 0.367s
9. Adrien Tambay Abt Audi 1m34.237s + 0.435s
10. Joey Hand RMG BMW 1m34.247s + 0.445s
11. Christian Vietoris HWA Mercedes 1m34.259s + 0.457s
12. Bruno Spengler Schnitzer BMW 1m34.286s + 0.484s
13. Filipe Albuquerque Rosberg Audi 1m34.318s + 0.516s
14. Jamie Green HWA Mercedes 1m34.462s + 0.660s
15. David Coulthard Mucke Mercedes 1m34.482s + 0.680s
16. Ralf Schumacher HWA Mercedes 1m34.598s + 0.796s
17. Miguel Molina Phoenix Audi 1m34.607s + 0.805s
18. Rahel Frey Abt Audi 1m34.666s + 0.864s
19. Andy Priaulx RBM BMW 1m34.804s + 1.002s
20. Roberto Merhi Persson Mercedes 1m35.077s + 1.275s
21. Robert Wickens Mucke Mercedes 1m35.149s + 1.347s
22. Susie Wolff Persson Mercedes 1m35.310s + 1.508s