The Andretti Autosport driver took a lights-to-flag victory on Sunday in Rome after starting from pole, leading every lap and taking the bonus point for the fastest lap.
It means the Briton is 24 points clear of Nick Cassidy in the championship standings after the Envision Racing driver was collected by fellow Kiwi Mitch Evans early in the race which meant neither driver scored points.
Dennis had stated on Saturday after finishing fourth that it would have been difficult to beat Evans and Cassidy on pure pace after they finished first and second but praised his team for turning things around.
“A really good day. We didn’t expect it after yesterday’s performance where we were obviously lacking some pace, but we managed to turn it around and come home with the perfect day,” he said.
“Obviously unfortunate that Mitch and Nick DNF’d but I felt like we still had the pace to win the race even with them there.
“I think it was a good race as a whole and the team can be really proud of what they did overnight with the improvements, and we delivered the perfect result.”
Source: Autosport