HONG KONG — Germany's Daniel Abt was disqualified from Sunday's Hong Kong Formula E race after a post-race inspection ended his victory celebrations and handed the win to Swedish rival Felix Rosenqvist.
Audi Sport at first said it would appeal, then decided not to.
The Audi driver had taken the checkered flag on his 25th birthday after long-time leader Edoardo Mortara spun late in the second race of the season.
But an inspection of his car revealed that the FIA security stickers on the inverters and motors did not correspond with those declared on the car's technical passport.
The breach of technical and sporting regulations meant Abt lost his first victory and the overall lead in the all-electric series.
Saturday's race winner Sam Bird now heads the drivers' standings for DS Virgin Racing, with 35 points, two clear of French racer Jean-Eric Vergne.
Abt's team principal Allan McNish said in a statement that the team accepted they had made "a small mistake with big consequences" and apologized.
"We gained no advantage as a result of the administrative error and all parts fully complied to homologation and the technical regulations at all times," he said.
"Still, we accept the decision of the FIA and fully back the technical passport regulations."
Former F1 driver and Le Mans 24 Hours winner McNish was in his first weekend as a team principal, heading up Audi's Formula E involvement as a full works team.
"That we had a strong race performance on both days is a positive," said head of Audi Motorsport Dieter Gass. "But it goes without saying that we had a somewhat different idea of Sunday night."
Rosenqvist's victory was the second of his Formula E career. The Mahindra driver had spun out of the lead from pole at the first corner but recovered to second place after Mortara then spun his Venturi car with less than three laps left.
New Zealand's Mitch Evans was promoted to third to give Jaguar their first podium finish in the all-electric series they joined last year.
Audi, in its first weekend as a full works entry, was also fined 5,000 euros ($5,944) for a separate infringement.
Five Audi team members walked onto the track to get to the podium before the final car had entered parc ferme, which the stewards deemed a "serious breach of safety regulations."
In Saturday's race, Bird won his sixth career FE victory but was penalized when he overshot his pitstop and rammed into the side of the Virgin garage, forcing a couple of team personnel to jump out of the way.
"I hit quite a lot going into the garage," Bird added. "The pit-lane is really filthy dirty and I tried to attack my pit-box as they have given us an almost impossible amount of time to do the pit-stop. But the car just went straight."
The series' had its first red flag in 35 races after a four-car log-jam on the opening lap and the race was suspended for more than 30 minutes before resuming under the safety car.
Meanwhile, four-time Formula One world champion Lewis Hamilton's attempt to show an interest in the series also backfired when he posted a clip on Instagram, which was subsequently deleted, criticizing driving standards.
The Briton expressed concern about former F1 driver Nick Heidfeld, whose car was seen flying through the air after a collision with French driver Nicolas Prost. The clip was from the very first Formula E race in Beijing in 2014.
Heidfeld posted a joking reply on Twitter from an airport on Monday, thanking Hamilton and assuring him that he had landed safely and was well.
The next Formula E race is in the Moroccan city of Marrakesh on Jan. 13.
Reporting by Ian Gordon