Verstappen started alongside polesitter Leclerc on the front row and ducked down the inside of the left-hand Turn 1 to grab the lead.
But, as grip was extremely limited on the brand-new surface, as evidenced by Fernando Alonso spinning off behind them and other drivers also making contact, Verstappen went deep into the run-off area, taking Leclerc with him.
Verstappen kept his lead while the stewards investigated the incident, and the Red Bull driver was soon handed a five-second penalty for pushing another driver off the track.
The world champion, who went on to take his 18th win of the season after a fierce challenge by the Ferrari man, admitted that he probably deserved his penalty even though behind the wheel he initially held a different opinion.
"We both braked quite late to defend the position, but I was a bit on the inside," said Verstappen.
"As soon as you go offline here, it's super low grip. And that's what happened. I braked and there was no grip.
"I didn't mean to push Charles off the track, but I couldn't slow it down and just kept sliding on four wheels wide.
"At the time, I was also full of adrenaline and I was unhappy with the decision. But, looking back at it, that was probably the right call."
Source: Autosport