The Envision Racing driver started on pole for the final Formula E race of the season at the ExCeL London’s indoor/outdoor circuit, which was twice red-flagged due to torrential rain.
Once uninterrupted green flag running got under way after conditions improved, Cassidy romped away at the front with only fellow Kiwi Mitch Evans able to keep within touching distance.
By the end of the 38-lap race Cassidy had stretched his lead to more than five seconds over the Jaguar driver, with newly crowned champion Jake Dennis a further 11s behind such was Cassidy’s dominance.
“I don’t know why but I just felt so comfortable, we had so much pace I could play with the race, which in this category is an unreal feeling because you don’t get those chances often,” said Cassidy, who is expected to leave Envision for Jaguar next season.
“I think the gap to Mitch was nearly five seconds in the end. I’m just really fortunate to have that car today and be in that position.
“I didn’t make a mistake. It was 38 laps in the end so it was a long race in those conditions.
“After what happened yesterday, I was just determined to do a mega job today.”
Cassidy had entered the final double-header of the season with a chance of the drivers’ title, but a collision with team-mate Sebastien Buemi in Saturday’s race curtailed his own title ambitions.
But victory in Sunday’s race, with Buemi finishing sixth, ensured that customer-Jaguar squad Envision claimed the teams’ title by 12 points over the factory outfit.
Envision team principal Sylvain Filippi praised the squad, which claimed its maiden teams’ title having been in Formula E since the championship’s inception.
“Seb in his first year with us has been strong, showing good pace, and Nick has been nothing short of exceptional and the car is fantastic,” he said.
“It’s the first time in Formula E we have a car that is pretty much quick everywhere and without that we cannot really do it.
“It’s the team, the drivers, the car and when you put it together it works but as you saw it’s very close.
“I have every faith in my team and after nine years of doing this, it took a while but it was amazing to get it.”
