Brad Keselowski had a chance at his third win of the season, but a late penalty with four laps to go ended his chances of winning the race.
Keselowski was penalized for driving through more than three pits, which eventually allowed Martin Truex Jr. to take the lead and win his fourth race of the year.
Truex had just enough fuel to hold off a surging Matt Kenseth, who was looking for his first win of the season and a berth in the playoffs.
Keselowski and Blaney ran low on fuel at the end of the race, which allowed Truex to take control. Earlier in the race, Truex was heard saying, "I hate these fuel mileage races." Yet, he was still able to save enough fuel to hold off for the victory to extend his lead atop the points standings.
"I can't believe that," Truex said. "It's so stressful to just let guys go by for the lead. I've never had to do that before."
This was Truex's first victory at Watkins Glen, and he said he remembers as a kid watching his dad race at the track.
Kenseth finished second behind Truex, followed by Daniel Suarez, Denny Hamlin and Clint Bowyer.
Truex did have enough fuel for a pretty sweet burnout after his win.
Truex extended his first place lead in the points, while Kyle Busch surpassed Kyle Larson for second place. Truex will go for his fifth win of the season Sunday at Michigan International Speedway.