Having already won the penultimate race of the season on Saturday to stretch his advantage to 27 points, Preining wrapped up the title in qualifying on Sunday after beating his title rival Mirko Bortolotti to pole position by 0.006s.
It gives him an unassailable 28-point lead in the standings, with only 25 on offer in the final race later in the afternoon.
Bortolotti needed to qualify on the front row and hope Preining set a lap that was no faster than fourth in order to remain in the hunt for the championship.
The Lamborghini driver set the fastest lap of the weekend on his first attempt, a 1m37.016s, before underlining his credentials with a blistering time of 1m36.806ss to consolidate his position at the top.
But Preining managed to go even quicker with just two minutes left in qualifying to end Bortolotti's title hopes, his time of 1m36.800s clinching him pole position for a second day in a row - and adding three crucial points to his tally.
The result makes him the first Porsche driver to win the DTM title, and only in the second year of the German manufacturer’s participation in the series.
Behind Preining and Bortolotti, HRT driver Luca Stolz qualified an excellent third with a time of 1m37.001s, leading the Mercedes contingent for a second consecutive qualifying session.
Outgoing champion Sheldon van der Linde bounced back from a difficult Saturday to put his Schubert BMW fourth on the grid, ahead of the Team Bernhard Porsche of Laurin Heinrich.
Emil Frey Ferrari’s Thierry Vermeulen secured his second-best starting position in sixth, ahead of the Abt Audi of Kelvin van der Linde.
Positions third to seven, between Stolz and van der Linde, were split by less than a tenth of a second in what was an ultra-close qualifying session behind the two title contenders who locked out the front row.
Christian Engelhart qualified eighth for Grasser Lamborghini after scoring a podium finish on his DTM return on Saturday, while Heinrich’s team-mate Ayhancan Guven and Landgraf Mercedes’ Maro Engel completed the top 10.
Abt’s Ricardo Feller, who sits third in the championship, was only 12th despite setting a time that was only four tenths off pole, while Winward Mercedes’ Lucas Auer was another leading driver to have a disappointing qualifying session as he ended up 18th.
Three-time DTM champion Rene Rast (Schubert) fared even worse as he could do no better than 23rd in the final qualifying of the season.
Qualifying results:
| Cla | Nº | Driver | Car / Engine | Time | Delay |
| 1 | 91 | Thomas Preining | Porsche | 1'36.800 | |
| 2 | 92 | Mirko Bortolotti | Lamborghini | 1'36.806 | 0.006 |
| 3 | 4 | Luca Stolz | Mercedes | 1'37.001 | 0.201 |
| 4 | 1 | S.van der Linde | BMW | 1'37.028 | 0.228 |
| 5 | 75 | Laurin Heinrich | Porsche | 1'37.048 | 0.248 |
| 6 | 69 | T.Vermeulen | Ferrari | 1'37.069 | 0.269 |
| 7 | 3 | K.van der Linde | Audi | 1'37.075 | 0.275 |
| 8 | 19 | C.Engelhart | Lamborghini | 1'37.110 | 0.310 |
| 9 | 24 | Ayhancan Guven | Porsche | 1'37.156 | 0.356 |
| 10 | 48 | Maro Engel | Mercedes | 1'37.165 | 0.365 |
| 11 | 14 | Jack Aitken | Ferrari | 1'37.174 | 0.374 |
| 12 | 7 | Ricardo Feller | Audi | 1'37.201 | 0.401 |
| 13 | 27 | David Schumacher | Mercedes | 1'37.243 | 0.443 |
| 14 | 11 | Marco Wittmann | BMW | 1'37.290 | 0.490 |
| 15 | 36 | Arjun Maini | Mercedes | 1'37.316 | 0.516 |
| 16 | 84 | Jusuf Owega | Mercedes | 1'37.403 | 0.603 |
| 17 | 90 | Dennis Olsen | Porsche | 1'37.427 | 0.627 |
| 18 | 22 | Lucas Auer | Mercedes | 1'37.476 | 0.676 |
| 19 | 8 | Luca Engstler | Audi | 1'37.509 | 0.709 |
| 20 | 40 | Mattia Drudi | Audi | 1'37.555 | 0.755 |
| 21 | 63 | Clemens Schmid | Lamborghini | 1'37.584 | 0.784 |
| 22 | 94 | Franck Perera | Lamborghini | 1'37.690 | 0.890 |
| 23 | 33 | René Rast | BMW | 1'37.708 | 0.908 |
| 24 | 99 | Marvin Dienst | Porsche | 1'37.729 | 0.929 |
| 25 | 83 | P.Niederhauser | Audi | 1'37.732 | 0.932 |
| 26 | 6 | Alessio Deledda | Lamborghini | 1'38.534 | 1.734 |
| 27 | 9 | Tim Heinemann | Porsche | 1'39.282 | 2.482 |
| 28 | 56 | Sandro Holzem | BMW | 1'39.308 | 2.508 |
