Daniel Abt’s scratch had already been itched two months before in Mexico City. In the rarefied atmosphere of the Aztec cauldron he had finally delivered, and so had Audi.
But there was a feeling that Abt still had a point to prove: he needed to dominate a race.
He knew it was something of which he was capable but many in the paddock were still sceptical whether he could do it against him teammate on an equal pegging.
At Berlin in May, the doubts were finally put to bed. Abt delivered, and then some.
The German had almost lost count of the times he had been denied top results and even in the case of Hong Kong (on his birthday!) the win was taken from the record books by, of all things, a barcode.
There was so much salt in the wounds of his Formula E career that he was almost anticipating the next twist of the cellar.
In Berlin it all changed and Abt dominated a race in which Audi had perhaps the biggest pace advantage seen since Sebastien Buemi turned the 2015 Beijing E-Prix into his own private plaything.
Audi’s renaissance was clinical. The forensic studies into the tiny PCP part in its inverter had paid off.
The e-tron FE04s were now reliable as well as fast and from Mexico City in March to the end of the season, Abt and di Grassi accrued a colossal 252 points to take the teams’ title.
Abt was sublime in Berlin. He backed up pole with the fastest lap in the race. Leading every inch of every lap? A breeze. Defeating teammate di Grassi? Done.
A blemish-free performance and one only dreamed about. Over an entire career these days, events like this only come about once or twice and for it to happen here on his home patch was a delight to behold.
For Audi it was an important milestone as it jettisoned all the doubt from its wretched start to the campaign in one afternoon.
“It was important for us yes, very important,” Allan McNish said after the race. “Daniel was something else wasn’t he, absolutely bullet proof, what a drive.”
Afterwards di Grassi muttered something about a vibration. His car was stripped back at base and while no doubt the champion was not at ease with his car as he usually is, the facts were that no one on earth that day was going to beat Abt.
Di Grassi was brilliant for the most part in Season Four but on Abt’s day of days in Berlin he was beaten plain and simple.
Did it trigger a cooling of the relationship between the two drivers? One that played out with the Brazilian’s overly aggressive move for the lead in New York six weeks later?
Who knows, but certainly Abt proved a lot of people wrong that day at Tempelhof and perhaps freed himself from the doubt of others, for good.