Sam Hornish Jr. was second, followed by Brendan Gaughan, Drew Herring and Sadler, who reclaimed the season points lead from Stenhouse.
Dillon seemed destined for a runner-up run behind Sadler, who got an opening when Stenhouse collided with Eric McClure on pit road on lap 33.
That handed the lead to Sadler, and he began pulling away.
But Sadler encountered steering issues with 50 laps left and was forced to make pit stops for corrections.
Sadler has a four-point lead over Stenhouse, who finished 17th. Dillon is 19 points back.
Dillon, who won the pole, completed a season sweep at Kentucky.
He dominated the June race, leading 192 of 200 laps.
FORMULA ONE: In Singapore, McLaren driver Lewis Hamilton claimed pole position for the Singapore Grand Prix.
Hamilton gave McLaren its fourth consecutive pole for the first time since 1999, and his victory chances in today’s race were boosted by Williams’ Pastor Maldonado earning a surprise second place in qualifying.
TRUCKS SERIES: In Sparta, Ky., James Buescher won a wreck-filled race Friday night to complete a Kentucky Speedway season sweep.
Buescher used strong pit stops and restarts to stay in contention before pulling away en route to his fourth victory of the year.
Buescher moved to second in the standings, four points behind Ty Dillon.
Parker Kligerman was second in the race, and Dillon finished third.
The first half of the race included five cautions totaling 34 laps, denying many of the contenders the long green-flag runs they wanted.
Pole-sitter Joey Coulter was fourth, and Brian Scott fifth.
Coulter set the early pace, though Buescher made his first charge to run second by lap 14.
That’s when the madness began, as Todd Bodine spun without contact coming out of turn 4. Things reshuffled quickly soon after on lap 21 as Johnny Sauter blew a tire and collected Tim George Jr. and Bodine, whose No. 11 Toyota sustained heavy damage and did not return.
The second caution lasted 12 laps as crews cleaned up debris.
Scott led the restart but Buescher won a door-to-door battle on the low side to take the lead with Nelson Piquet squeezing through for third. But then another yellow flag followed, as rookie Bryan Silas spun and brushed the turn 2 wall.
Ryan Blaney, the 18-year-old who became the series’ youngest winner last week at Iowa Speedway, finished 11th after starting 16th.
He struggled to get through the mess, but stayed out during the fourth caution caused by Brennan Newberry’s wreck in the backstretch and led on the restart at lap 50. Blaney cracked the top 10 late in the race before falling back.
Only 14 of 36 trucks finished on the lead lap.