With the track surface less abrasive than some of the other circuits used in the first half of the season, the drivers were able to complete as many as two push laps in one run.
Reigning champion Rast laid the initial benchmark with a time of 1m47.414s, the fastest lap of the weekend, before he was eclipsed by Muller’s 1m47.374s flyer.
Rast shot back on his second push lap to lap the circuit in 1m47.150s and, although Muller set the quickest time of everyone in the first sector, Rast held on to provisional pole by 0.027s.
The Team Rosberg driver improved further to 1m47.055s on his second run in qualifying, putting himself 0.122s clear of the championship leader.
However, Muller managed to regain the advantage on his final flyer, breaking the 1m47s barrier on his way to a stellar lap of 1m46.834s.
Rast opted against doing a second push lap on his final run, allowing Muller to claim his second pole position of the season by a healthy margin of 0.221s.
Robin Frijns, who had scored four pole positions in the opening eight races of the year, wasn’t in contention for a front-row start this time, qualifying half a second down on his Abt Audi teammate Muller in third.
Marco Wittmann finished as the strongest BMW driver in fourth, less than a tenth adrift of Frijns, but nearly seventh tenths slower than the pole time.
Audi's 2013 champion Mike Rockenfeller and WRT Audi driver Ferdinand Habsburg qualified fifth and sixth respectively, the two drivers separated by just 0.007s.
Sheldon van der Linde, who delivered BMW’s second victory of the season at Assen last weekend, was seventh, ahead of the Audis of Jamie Green and Loic Duval.
Philipp Eng made it three BMW drivers in the top 10, as the Bavarian brand again struggled against Audi on one-lap pace.
Robert Kubica finish 1.6s off the pace in 15th in the ART-run customer BMW, only out-qualifying the WRT Audi of Fabio Scherer.
Nurburgring DTM - Qualifying results:
|1||51|| Nico Müller ||Audi RS5 Turbo DTM 2020||1'46.834|
|2||33|| René Rast ||Audi RS5 Turbo DTM 2020||1'47.055||0.221|
|3||4|| Robin Frijns ||Audi RS5 Turbo DTM 2020||1'47.428||0.594|
|4||11|| Marco Wittmann ||BMW M4 Turbo DTM 2020||1'47.493||0.659|
|5||99|| Mike Rockenfeller ||Audi RS5 Turbo DTM 2020||1'47.549||0.715|
|6||62|| Ferdinand Habsburg ||Audi RS5 Turbo DTM 2020||1'47.556||0.722|
|7||31|| Sheldon Van Der Linde ||BMW M4 Turbo DTM 2020||1'47.631||0.797|
|8||53|| Jamie Green ||Audi RS5 Turbo DTM 2020||1'47.642||0.808|
|9||28|| Loic Duval ||Audi RS5 Turbo DTM 2020||1'47.751||0.917|
|10||25|| Philipp Eng ||BMW M4 Turbo DTM 2020||1'47.938||1.104|
|11||22|| Lucas Auer ||BMW M4 Turbo DTM 2020||1'47.968||1.134|
|12||16|| Timo Glock ||BMW M4 Turbo DTM 2020||1'48.034||1.200|
|13||27|| Jonathan Aberdein ||BMW M4 Turbo DTM 2020||1'48.096||1.262|
|14||10|| Harrison Newey ||Audi RS5 Turbo DTM 2020||1'48.206||1.372|
|15||8|| Robert Kubica ||BMW M4 Turbo DTM 2020||1'48.450||1.616|
|16||13|| Fabio Scherer ||Audi RS5 Turbo DTM 2020||1'48.935||2.101|
|View full results|