Buescher earned his first win in the Camping World Truck Series, to go with his maiden Nationwide Series victory at Daytona in February. It was the second consecutive victory for Turner Motorsports, which sent Kasey Kahne to Victory Lane last Saturday at Rockingham.
"Turner Motorsports trucks are pretty awesome," Buescher said. "Two in a row is saying something. Having our first win [for the team] last week with Kasey, and running second to him, we wanted to come here and win one for ourselves."
Keselowski ran third, followed by Nelson Piquet Jr. and Todd Bodine.
"We needed a bit more speed to run with James, who was just lightning quick," said Keselowski, who was attempting to become the 24th driver to win a race in each of NASCAR's top three touring series. "We didn't have anything for that, so hats off to his team and James himself.
"But we learned a lot, and hopefully we can take something away from it to help out Parker Kligerman [driver of Keselowski's full-time No. 29 entry] and his efforts running for the championship, so for that I'm thankful."
With the victory, Buescher narrowed Peters' lead in the series standings to four points. Ron Hornaday, Justin Lofton, Kligerman, rookie Ty Dillon and Miguel Paludo completed the top 10.
"He's been a factor all this year, and when we raced with him last year," Peters said of the race winner. "He's going be the one to contend for a championship, I feel like, and the RCR bunch are going to be ones to contend for the championship, and I think we are, too."
Dillon is fourth in the standings, 14 points behind Peters and three behind third-place Lofton.
Driving his own truck for the second time this season, Keselowski surged past Buescher and into the lead shortly after a restart on Lap 105 of 167. Buescher pursued patiently until Lap 122, when he cleared Keselowski through Turn 4 to regain the top spot.
The longer the run, the more Buescher's No. 31 Chevrolet flaunted its superiority. By Lap 140, with green-flag pit stops imminent, Buescher had opened an advantage of 5.4 seconds, with Peters closing in on Keselowski for the second position.
As the green-flag cycle began, Peters grabbed the No. 2 spot from Keselowski before heading to the pits on Lap 146. Buescher followed on Lap 150 and matched Peters with a four-tire stop. That left Keselowski, who took right-side tires only, in the lead, but Buescher quickly tracked down the No. 19 Ram and made the pass for the top spot on Lap 157.
The final 10 laps were a smooth cruise for the first-time Truck series winner.