The 25-year-old German, who also took pole at the same circuit last year, hustled his Abt Audi around the circuit in 1:18.689 to head the Mercedes of two-time Formula One World Champion Mika Hakkinen.
Canandian Bruno Spengler, who had been the man to beat in testing and practice, was unable to give Mercedes pole and had to settle for third place in his AMG-run machine, and Bernd Schneider made it three of the team's cars in the top four.
Britain's Jamie Green was the fourth of the AMG boys in fifth place, one place ahead of former champion and countryman Gary Paffett in his year-old Persson version.
Ralf set for DTM role
Timo Scheider, the second of the Abt Audi drivers, was a disappointing seventh with the Persson Mercedes of Alex Margaritis and Mike Rockenfeller's Rosberg Audi next up.
It was a bad day for Mattias Ekststrom. The Swede, who will be crowned champion for the second time if he wins the race and Tomczyk is no higher than sixth, will start in tenth place.
12th and 19th were the two-year-old Mercedes' of Paul di Resta - who still has a mathematical chance of winning the title if he can win the two remaining races - and Susie Stoddart.