The Brazilian kicked off the Audi team’s Formula E farewell weekend by holding off his Venturi Racing rival over the line by just 0.141s after Mortara had nailed his exit out of the final corner to tee up a sprint to the finish.
This came as the front row-sitting DS Techeetahs of polesitter Jean-Eric Vergne and Antonio Felix da Costa lost a provisional drivers’ and teams’ points lead as they shipped places.
Vergne had launched his car soundly enough from the left-hand side of the grid to keep da Costa at bay at the Tempelhof Airport track snaked into the sweeping Turn 1.
Reigning champion da Costa then settled into a comfortable second, 0.5s behind his team-mate, with di Grassi the same distance behind, as an eventless procession broke out.
However, after a six-lap stalemate, the safety car was then called into action when New York City victor Sam Bird ground to a halt on the main straight with suspected driveshaft failure after a series of opening lap knocks from Porsche’s Andre Lotterer into Turn 10.
Di Grassi was slow away from third place at the restart, allowing fourth-starting Mortara to massively pile on the pressure before bailing out of his attempted move through Turn 1.
Still the DS Techeetahs appeared to reign supreme, albeit with da Costa taking the lead on lap 18 after an instruction from his race engineer to “use energy” to swap positions.
Jean-Eric Vergne, DS Techeetah, DS E-Tense FE21, Antonio Felix Da Costa, DS Techeetah, DS E-Tense FE21
Photo by: Simon Galloway / Motorsport Images
That switcheroo enabled di Grassi to close to the rear of Vergne, and then the two-time champion appeared to suffer with a lack of grip at the rear and fell down the order.
He lost out also to the rapid attack mode-enhanced Audi of Rene Rast and Jake Dennis.
As da Costa moved off-line for his 35kW attack mode boost at Turn 6, it allowed Norman Nato to follow Mortara through for a Venturi Racing 1-2.
Di Grassi was able to close back up to Nato and neatly sold the rookie a dummy into Turn 10 to cut back for second place.
He then pounced for first place by using attack mode and carrying massive overspeed down the main straight to sweep by in plenty of time before the stop into Turn 1.
From there di Grassi held firm until Mortara made one last challenge in the final lap, attempting to make a final corner charge come to pass – but the Audi driver hung on.
Mortara crossed the line second as Jaguar Racing’s Mitch Evans clambered up two places to snare a fifth podium of the season, the best of the field, after a precise sweep across the front of Nato through the Turn 8 high-speed right-hand kink.
Edoardo Mortara, Venturi Racing, 2nd position, Lucas Di Grassi, Audi Sport ABT Schaeffler, 1st position, Mitch Evans, Jaguar Racing, 3rd position, on the podium
Photo by: Rudy Carezzevoli / Motorsport Images
Nato, incidentally fighting for his seat amid rumours of a di Grassi move to Venturi Racing, missed out on his maiden podium by 0.09s as Jake Dennis landed fifth for BMW Andretti.
The DS Techeetahs stemmed the loss of positions entering the final third of the race as da Costa battled a lack of regen braking into Turn 1 before handing back track position.
That brought Vergne home in sixth and da Costa seventh as Maximilian Guenther landed eighth ahead of Rast, the Audi declining after an initial storming run to third behind di Grassi with yet another fastest race lap point.
Lotterer emerged from the tussle with Bird largely unscathed to snare 10th as Sebastien Buemi slipped from sixth to 11th for Nissan e.dams.
Mercedes driver Stoffel Vandoorne climbed 10 places but ultimately finished without points in 12th, while Robin Frijns landed 15th and de Vries classified only 22nd after pitting following contact with Alex Lynn.
That means de Vries holds a very slender three-point lead over Mortara ahead of the final race of the season, while DS Techeetah lost its initial teams’ lead to Jaguar Racing.