"After I took that second set of blacks I started getting in-sync with the car and the balance started coming to me," Hunter-Reay said. "I was really worried at the beginning because it was really loose.
"But once I got into a rhythm the car was doing everything I needed it to do.
"It was such a great car."
This year's Indianapolis 500 winner Will Power finished second while Dixon's Chip Ganassi teammate Ed Jones completed the podium.
Power took over the lead of the championship while Dixon as just a handful of points back in second.
Dixon's fourth place finish capped a top weekend for the four-time championship winner. He won his 42nd career race on Sunday to move into a share of third all-time alongside Michael Andretti. He still trails legendary AJ Foyt and Mario Andretti by a long way.
The race was delayed by over half an hour after the safety car crashed during the warm-up lap in an embarrassing moment for the series. Cars were forced back into the pits while they cleaned up the mess and removed the damaged car.
The series moves back to an oval track next week at Texas Motor Speedway.
