Factory Lamborghini driver Bortolotti led the first part of the race with ease from pole position, putting several seconds between himself and the chasing pack led by the Winward Mercedes of Auer.
But the race was turned on its head on lap 19 when Bortolotti’s Grasser Racing team-mate Rolf Ineichen stopped on track at Turn 1 shortly after his pitstop, bringing out the safety car.
After a brief intervention period, Bortolotti's Lamborghini was simply slow to accelerate when the race resumed and he tumbled down the order, allowing Auer to come through and take the lead of the race.
From there on, the Austrian was untouchable out front, clinching his eighth-career victory in the DTM by just over a second.
HRT Mercedes driver Luca Stolz made rapid gains after an early pitstop on lap 8, finishing a strong second in his first DTM race as a full-timer.
Bortolotti recovered from his botched safety car restart to claim the final spot on the podium, repassing the GruppeM Mercedes of Maro Engel into Turn 1 on the last lap of the race.
Engel was later hit with a five-second penalty for a pitstop infringement, dropping to 10th place in the final ranking.
This promoted last year’s title contender Kelvin van der Linde to fourth in the Abt Sportsline Audi, the South African recovering from a poor qualifying that left him 17th on the grid in the 29-car field.
Porsche drivers also showed improved race pace after struggling in qualifying, with Dennis Olsen finishing a strong fifth for the SSR Performance team on the Stuttgart-based marque’s debut in the DTM, three places ahead of team-mate Laurens Vanthoor.
Abt Audi’s Ricardo Feller profited from an early pitstop on lap 6 and that allowed the reigning GT Masters champion to finish sixth on his DTM debut.
Schubert Motorsport’s Sheldon van der Linde piloted the new BMW M4 to a solid seventh place ahead of Vanthoor, while team-mate Philipp Eng jumped from 24th on the grid to finish ninth on his DTM return.
The final points-paying position went to Engel after his five-second penalty, while reigning champion Maximilian Gotz in his Winward Mercedes could only manage 11th at the start of his title defence.
Aston Martin factory driver Nicki Thiim, driving for T1 Motorsport Lamborghini, ran inside the top five for much of the race but was caught up in the melee at the restart, tumbling to a disappointing 12th in the final order.
The chaos at the restart also impacted Red Bull’s Felipe Fraga and three-time champion Rene Rast in the Abt Audi, both retiring from the race immediately with damage to their cars. Fraga was running in seventh place and was hoping to take advantage of fresher tyres, having made his mandatory stop just a lap before the safety car was deployed.
Nico Muller (Team Rosberg) and Marco Wittmann (Walkenhorst BMW) were the other high-profile retirees from the race, both peeling into their respective garages early on with unrelated issues.
On his DTM debut as a replacement for Nick Cassidy, nine-time World Rally champion Sebastien Loeb was classified 16th in his AlphaTauri-sponsored Ferrari.
DTM Portimao race one results - 32 laps:
| Cla | Driver | Car | Time | Gap |
|---|---|---|---|---|
| 1 |  Lucas Auer | Mercedes-AMG GT3 Evo | 57'55.325 | |
| 2 |  Luca Stolz | Mercedes-AMG GT3 Evo | 57'56.176 | 0.851 |
| 3 |  Mirko Bortolotti | Lamborghini Huracán GT3 Evo | 57'57.136 | 1.811 |
| 4 |  Kelvin van der Linde | Audi R8 LMS Evo II | 57'58.378 | 3.053 |
| 5 |  Dennis Olsen | Porsche 911 GT3 R | 57'58.731 | 3.406 |
| 6 |  Ricardo Feller | Audi R8 LMS Evo II | 57'59.730 | 4.405 |
| 7 | Sheldon Van Der Linde | BMW M4 GT3 | 58'00.093 | 4.768 |
| 8 |  Laurens Vanthoor | Porsche 911 GT3 R | 58'00.690 | 5.365 |
| 9 | Philipp Eng | BMW M4 GT3 | 58'02.724 | 7.399 |
| 10 | Maro Engel | Mercedes-AMG GT3 Evo | 58'02.793 | 7.468 |
| 11 | Maximilian Götz | Mercedes-AMG GT3 Evo | 58'03.859 | 8.534 |
| 12 |  Nicki Thiim | Lamborghini Huracán GT3 Evo | 58'04.466 | 9.141 |
| 13 | Thomas Preining | Porsche 911 GT3 R | 58'07.805 | 12.480 |
| 14 | Esteban Muth | BMW M4 GT3 | 58'08.628 | 13.303 |
| 15 |  Mikael Grenier | Mercedes-AMG GT3 Evo | 58'09.077 | 13.752 |
| 16 |  Sébastien Loeb | Ferrari 488 GT3 Evo 2020 | 58'09.610 | 14.285 |
| 17 |  Arjun Maini | Mercedes-AMG GT3 Evo | 58'10.300 | 14.975 |
| 18 | Marius Zug | Audi R8 LMS Evo II | 58'11.385 | 16.060 |
| 19 | Maximilian Buhk | Mercedes-AMG GT3 Evo | 58'12.026 | 16.701 |
| 20 | David Schumacher | Mercedes-AMG GT3 Evo | 58'12.589 | 17.264 |
| 21 | Clemens Schmid | Lamborghini Huracán GT3 Evo | 58'13.356 | 18.031 |
| 22 | Alessio Deledda | Lamborghini Huracán GT3 Evo | 58'21.267 | 25.942 |
 Esmee Hawkey | Lamborghini Huracán GT3 Evo | 43'00.433 | 9 Laps | |
| René Rast | Audi R8 LMS Evo II | 41'03.303 | 10 Laps | |
 Felipe Fraga | Ferrari 488 GT3 Evo 2020 | 39'02.903 | 11 Laps | |
| Rolf Ineichen | Lamborghini Huracán GT3 Evo | 27'50.431 | 16 Laps | |
| Marco Wittmann | BMW M4 GT3 | |||
 Dev Gore | Audi R8 LMS Evo II | |||
| Nico Müller | Audi R8 LMS Evo II | 5'37.472 | 29 Laps | |
| View full results | ||||
