The Andretti driver made what would be the race-winning move on Lap 12, with the Brit taking advantage of an opening left by di Grassi.
From there, Dennis stretched his lead, and through three Safety Car periods, he was able to run away with the race lead, eventually heading home Wehrlein by a huge seven seconds.
Last year’s winner in Mexico, Wehrlein pushed to an eventual 11-second margin on third-placed di Grassi, having clambered up from sixth on the grid. Both drive Porsche-powered cars, with the German manufacturer finishing up with four of their powertrains in the top ten.
Although Di Grassi started in pole, he found himself on the defensive entering the final third of the race and it took all the Brazilian’s guile to see off the attentions of NEOM McLaren Formula E Team’s Jake Hughes over the closing stages.
Eventually, the rookie would be preoccupied with Lotterer looming in his mirrors, relieving the pressure on di Grassi. Lotterer, who moved to the Porsche-powered Andretti team in the off-season, went past Hughes’ McLaren on the inside at the hairpin on the final lap.
Fifth was no disappointment for Hughes on debut; the rookie more than impressing ever since he took the McLaren seat at testing in Valencia. He headed home a resurgent Sebastien Buemi – the Swiss having moved from Nissan to Envision Racing over the winter.
Season 6 champion António Félix da Costa added to Porsche’s tally with seventh spot on the day, fighting his way up through the points positions late-race with a belated ATTACK MODE. Mitch Evans quietly claimed points and eighth for Jaguar TCS Racing, Nick Cassidy made it two Envision Racing cars in the points with ninth, while reigning champion Stoffel Vandoorne could only steer his DS PENSKE to a single point from 14th on the grid.
Dennis sealed the TAG Heuer Fastest Lap.
Rounds 2 and 3 of the ABB FIA Formula E World Championship take place in Diriyah, Saudi Arabia, on Friday 27 January and Saturday 28 January.
Jake Dennis, No. 27, Avalanche Andretti Formula E, said:
“The fans here have been sensational. In that final lap I could really hear them cheering. To start on the front row and then win by that much, with a Porsche one-two, so big shout out to my team.
“It was such a physical race. These cars are so hard to drive physically and with the lower grip as well, it makes everything more challenging. But it’s even more rewarding, especially when you win by five seconds. Time for some tequila with the team, an incredible race.
“My team and I have such a good relationship together. We just work so well. It didn’t look like it was happening in qualifying, we turned it round, made some small adjustments for the race and absolutely nailed it. Big kudos to my guys, this is a small repayment to them and hope to have more success because Saudi isn’t that far away.”
Pascal Wehrlein, No. 94, TAG Heuer Porsche Formula E Team, said:
“Great way to start the season, this place was awesome. When you start in P6 and end up in P2 – that’s really really good. I’m very grateful to the car and my teammates for this, I think the last couple of months we have really put in some hard work – especially the last couple of weeks after Valencia – I just want to thank everyone in the team for their hard work. We have a clear goal this season, and that’s the best way to start it.
“It seemed like the pace in the race was really good, even in qualifying all the Porsche cars were super strong. We hope it is not a one-off and we keep working hard. Last year Mexico has also been our best race, so we have to make sure we keep working hard to understand the car really well and to make progress. We want to fight for the championship and it’s a good way to start.
Lucas di Grassi, No. 11, Mahindra Racing, said:
“It was a very very tough race, of course we know in this race that the Porsche’s are really fast, remember last year they won P1, P2 and they disappeared. It was impossible to hold Jake and Pascal, I was running low on energy but I tried to defend as much as I could. In the end a podium is like a win for us with only three or four days in this car, there is so much potential to take it out further, so I am very happy.”