Marco Wittmann topped the first day of the final DTM pre-season test at Hockenheim on Monday.
The RMG BMW driver topped both of the day's sessions, setting a best of 1m33.769s in the morning, before improving to a 1m33.084s in the afternoon.
Mattias Ekstrom finished the day second fastest with a 1m33.316s best, completing the most laps of any driver with 141 over the course of the day.
The two-time champion was followed on the timesheets by fellow Audi drivers Timo Scheider, Edoardo Mortara and Nico Muller.
Joey Hand was sixth fastest for BMW, while the best Mercedes runner of the day was Daniel Juncadella, who was seventh, and more than 1.1 seconds off the pace, in the Mucke Motorsport entry.
Ex-Formula 1 driver Paul di Resta completed the most laps in the morning session in his Mercedes, but his best time from that session was only good enough to leave him 10th in the 11-car field.
This week's test runs for four days, finishing on Thursday.
Pos Driver Car Time Gap 1. Marco Wittmann RMG BMW 1m33.084s 2. Mattias Ekstrom Abt Audi 1m33.316s +0.232s 3. Timo Scheider Abt Audi 1m33.590s +0.506s 4. Edoardo Mortara Abt Audi 1m33.828s +0.744s 5. Nico Muller Rosberg Audi 1m33.944s +0.860s 6. Joey Hand RBM BMW 1m34.061s +0.977s 7. Daniel Juncadella HWA Mercedes 1m34.195s +1.111s 8. Timo Glock MTEK BMW 1m34.340s +1.256s 9. Bruno Spengler Schnitzer BMW 1m34.360s +1.276s 10. Paul Di Resta HWA Mercedes 1m34.761s +1.677s 11. Christian Vietoris HWA Mercedes 1m35.147s +2.063s