It was Busch's fourth series win of the season and 17th overall spanning all three of NASCAR's national series.
Busch and Keselowski ran side-by-side for a large portion of the race, trading the lead several times as they combined to lead 102 of the 150 laps.
"Finally got by him and he was still with me, and I started stretching him and thought I could breathe again," Busch said. "Then two laps later, he was on my butt again."
Busch was startled on his celebratory burnout when he leaned out the window while mimicking a boxer -- an attempt to show he'd outdueled someone -- and his truck ran out of fuel. It looked as if it nearly caused Busch to fall out the window.
Busch, who will try for the weekend sweep at Chicago by winning the Nationwide race on Saturday and the Sprint Cup race on Sunday, laughed it off later.
"Always try to do something. Keep it fresh. I'm running out of ideas," he said.
Keselowski had to settle for his second runner-up finish of the season and fifth of his career. Keselowski is still searching for his first career Truck Series victory.
"Running this race, side-by-side, every restart, some pack racing, that's just something that I think is exceptional to watch," Keselowski said. "But from my place is exceptional to do. A little disappointed we didn't get the win, but I know we were close. I know how far our team and company has come."
Ryan Blaney finished third driving for Keselowski.