This is not the first time a Tesla model has entered Germany's top 10. The Model 3 sedan was No. 3 and No. 2 in February and March, respectively.
Tesla, however, has prioritized the Model Y, which it builds at its German plant outside of Berlin. Last month the Model Y outsold the Model 3 by a ratio of 5 to 1, according to market researcher Dafaforce.
Germany's main driver of growth last month was the fleet market, which rose 21 percent to 67,004 units, Dafaforce's figure show.
"Easing supply chain disruptions meant that fleet managers finally got deliveries of cars they ordered months ago," Dataforce Senior Automotive Analyst Benjamin Kibies said.
The resurgence of the sector was beneficial to the VW, Mercedes-Benz, Audi, BMW and Skoda brands, which are popular with German fleet managers.
Audi passed BMW,17,499 to 16,039, to become Germany's No. 3-selling brand on strong demand for popular fleet cars such as the A4 sedan, which was up 32 percent last month.
VW and Mercedes finished the month No. 1 and No. 2, respectively, in overall sales, with Skoda rounding out the top five.
The fastest growing brand in Germany, however, was focused on the retail market.
Dacia's registrations grew by 76 percent to 5,627 units, which made the Renault Group budget brand Germany's No. 11-seller in August.
Dacia was lifted by two new models, the Spring and the Jogger.