Nico Muller emerged from DTM free practice at Moscow Raceway as the pacesetter, finishing on top of an Audi 1-2-3 in the second session.
The rookie was third fastest in the first hour long session, before improving on his morning time by more than half a second in the afternoon to set a best of 1m28.993s - the only time below 1m29s.
Reigning champion and winner of last year's race Mike Rockenfeller ended the day second fastest.
The Phoenix driver jumped to the top of the second session with a 1m29.080s best 26 minutes in, before improving to a 1m29.007s five minutes from the end, having just been displaced from P1 by Muller.
Mattias Ekstrom was in the top three in both sessions, going second fastest in FP1, before a late 1m29.11s lap put him third in FP2.
BMW's Maxime Martin was another late improver in FP2, going fourth fastest on his final flying lap, making him the best non-Audi in the second session.
However, the best overall BMW performance of the day was points leader Marco Wittmann. The young German was fastest in the morning session with a 1m29.101s, the third fastest time of the entire day.
He couldn't quite replicate the same pace in the second session, finishing seventh, behind Timo Glock and Miguel Molina.
After success on the streets of Nuremberg last time out, Mercedes had a tough day in Moscow.
Gary Paffett set the best time for a Mercedes driver across the two sessions with a 1m29.420s in the second session, which left him ninth fastest.
In the first session, Pascal Wehrlein was the best-placed Mercedes also in ninth, while Norisring winner Robert Wickens could manage just 18th and 19th across the two sessions.
Practice 1 Pos Driver Team/Car Time Gap Laps 1. Marco Wittmann RMG BMW 1m29.101s 22 2. Mattias Ekstrom Abt Audi 1m29.555s +0.454s 27 3. Nico Muller Rosberg Audi 1m29.559s +0.458s 25 4. Miguel Molina Abt Audi 1m29.613s +0.512s 27 5. Maxime Martin RMG BMW 1m29.616s +0.515s 24 6. Augusto Farfus RBM BMW 1m29.710s +0.609s 27 7. Mike Rockenfeller Phoenix Audi 1m29.735s +0.634s 27 8. Joey Hand RBM BMW 1m29.780s +0.679s 28 9. Pascal Wehrlein HWA Mercedes 1m29.821s +0.720s 25 10. Adrien Tambay Abt Audi 1m29.875s +0.774s 25 11. Martin Tomczyk Schnitzer BMW 1m30.059s +0.958s 25 12. Timo Scheider Phoenix Audi 1m30.089s +0.988s 27 13. Edoardo Mortara Abt Audi 1m30.129s +1.028s 16 14. Bruno Spengler Schnitzer BMW 1m30.155s +1.054s 22 15. Vitaly Petrov Mucke Mercedes 1m30.328s +1.227s 31 16. Jamie Green Rosberg Audi 1m30.388s +1.287s 30 17. Antonio Felix da Costa MTEK BMW 1m30.476s +1.375s 21 18. Robert Wickens HWA Mercedes 1m30.507s +1.406s 21 19. Timo Glock MTEK BMW 1m30.557s +1.456s 24 20. Daniel Juncadella Mucke Mercedes 1m30.699s +1.598s 23 21. Christian Vietoris HWA Mercedes 1m30.718s +1.617s 19 22. Gary Paffett HWA Mercedes 1m30.767s +1.666s 24 23. Paul di Resta HWA Mercedes 1m30.829s +1.728s 22 Practice 2 Pos Driver Team/Car Time Gap Laps 1. Nico Muller Rosberg Audi 1m28.993s 23 2. Mike Rockenfeller Phoenix Audi 1m29.077s +0.084s 25 3. Mattias Ekstrom Abt Audi 1m29.112s +0.119s 26 4. Maxime Martin RMG BMW 1m29.121s +0.128s 23 5. Timo Glock MTEK BMW 1m29.125s +0.132s 26 6. Miguel Molina Abt Audi 1m29.203s +0.210s 23 7. Marco Wittmann RMG BMW 1m29.332s +0.339s 23 8. Bruno Spengler Schnitzer BMW 1m29.345s +0.352s 23 9. Gary Paffett HWA Mercedes 1m29.420s +0.427s 18 10. Daniel Juncadella Mucke Mercedes 1m29.467s +0.474s 22 11. Edoardo Mortara Abt Audi 1m29.499s +0.506s 23 12. Jamie Green Rosberg Audi 1m29.634s +0.641s 27 13. Joey Hand RBM BMW 1m29.682s +0.689s 23 14. Augusto Farfus RBM BMW 1m29.696s +0.703s 23 15. Adrien Tambay Abt Audi 1m29.733s +0.740s 23 16. Timo Scheider Phoenix Audi 1m29.804s +0.811s 25 17. Paul di Resta HWA Mercedes 1m30.011s +1.018s 23 18. Christian Vietoris HWA Mercedes 1m30.044s +1.051s 26 19. Robert Wickens HWA Mercedes 1m30.076s +1.083s 19 20. Martin Tomczyk Schnitzer BMW 1m30.208s +1.215s 24 21. Pascal Wehrlein HWA Mercedes 1m30.230s +1.237s 22 22. Vitaly Petrov Mucke Mercedes 1m30.529s +1.536s 19 23. Antonio Felix da Costa MTEK BMW No time set