Harman opened his final round at the Barclays with a pair of bogeys then holed his tee shot on the par-3 third hole with a 7-iron from 184 yards.
A day earlier in Round 3, Harman double-bogeyed No. 3.
He played the next 10 holes at 2 over before dropping another ace at the par-3 14th. Harman hit a 4-hybrid from 220 yards for the second hole-in-one to get back to even par for the day.
"It was a bad, bad day to do it," Harman said laughing, referring to the golf tradition where those who make a hole-in-one also buy the drinks. "All of us are going into [New York City] tonight. I would have much rather had it yesterday."
Asked how much the tab might be, Harman replied, "It's going to hurt. ... It's going to hurt real bad."
In 121 career PGA Tour events, Harman never had an ace. His last 1 on the scorecard came in high school, he said, but it's not like it never happened to him. The 78th-ranked player in the world said he has had six or seven holes-in-one during nontournament rounds playing with friends.
Often a hole-in-one at a PGA Tour event wins the golfer a car, a luxury watch or some other perk. "How is one of those not a car?" Harman joked.
Harmon shot 68 on Sunday and finished the tournament at 2 under.
According to the PGA Tour, the other two double aces came in 2006 by Yusaku Miyazato at the Reno-Tahoe Open and in 1955 by Bill Whedon at the Insurance City Open.
Harman has missed three of his past four cuts, including at The Open and the PGA Championship, but he reached the weekend at Plainfield Country Club and will advance to the Deutsche Bank Championship next week at TPC Boston for the second event of the FedEx Cup playoffs.