After the TAG Heuer Porsche of Pascal Wehrlein got the lead on lap four, Dennis could not make any passes and was angry with the German's defensive techniques.
"I'm pretty annoyed to be honest," he said after the Gulavit Jakarta E-Prix. "You're obviously having a good season if you're annoyed at second."
Lining up in second on the grid after battling Maximilian Guenther (Maserati MSG Racing) in the Final of the qualifying Duels, Dennis had a poor start from the dirtier side of the grid that saw him lose several positions as the lights went green.
"Obviously, the start lost me the race. Ultimately, we had too much wheel spin on the dust and dropped back to fourth. Then the manoeuvre with Pascal was ridiculous. I had to hit so much pressure to avoid hitting the back of him. I don't know how he got away with that, to be honest, it's ridiculous.
"The other two guys did it perfectly. They left just enough space for one car, which is the rule. Then Pascal completely swerved up to the wall, and I had to slam the brakes halfway down the straight. He'd already committed to lifting, and at that point, you have to leave space, and he didn't. But we can't protest against them because they have a Porsche powertrain."
Avalanche Andretti is a customer team of the factory TAG Heuer Porsche outfit, with both entries using the Porsche 99X Electric GEN3 cars. Being sister teams has proved successful, especially at the start of the season with three consecutive 1-2 results for the Porsche powertrain. Yet, this is one of the first sights of tension between the two teams.
When asked what Dennis has learnt for tomorrow's Jakarta race, he stressed how much he wanted to start on the clean side of the grid.
"Qualifying is super important. I didn't expect the race to go like that. It was flat out from the start. We have a really quick qualifying car, it's not as quick as Max [Guenther's], but if we can start on the front two rows, we can win the race tomorrow.
Sweltering in the hot Jakarta sun and with very high humidity, this race weekend is going to be one of the most challenging for the drivers. Taking a seat to do another post-race debrief with the Formula E broadcast team, Dennis added that the race felt like "36 qualifying laps in a row" due to its intense nature, which he didn't predict.
"I did two pretty ballsy moves before that on Stoffel Vandoorne (DS PENSKE) and Guenther, and they left me just enough room, as they should. It was on the dust and on the limit. But Pascal's move was a bit aggressive. For me, it was a bit on the limit, but we go home with 18 points, and Nick Cassidy (Envision Racing) finished seventh."
Cassidy, who currently leads the Drivers' World Championship, seemed to struggle throughout parts of the E-Prix. As a result of Wehrlein's victory, there are now just two points between Cassidy and Saturday's race winner. Dennis still remains third in the standings on 114 points compared to Cassidy's 128.