"The rough here is terrible," said Perry, returning from an eye injury that forced him to withdraw after the first round of the PGA.
The 48-year-old Perry, a three-time winner this season, wondered how Mahan managed to shoot a 62 on the tree-lined course that places a premium on accurate driving.
"It never ceases to amaze me, the PGA Tour," Perry said. "There are tournaments where I'll shoot 6 or 7 under and that's as good as I can play and the winner is 21 under and I'm thinking, `How did they do that? Did they quit after 15 or what?"'
Harrington, the 2005 winner at Westchester, made a double bogey on 18 - his ninth hole - and also had a 6 on the 586-yard par-5 third.
"I know it's difficult out there and the rough is tough, but that was just bad play," the Irish star said.
Mahan had his fifth 62 in five full seasons on the tour. Last year, he opened with a 62 en route to a playoff victory in the Travelers and also matched his career best in the Canadian Open and at Westchester, the tournament site the previous 41 seasons.
"When he gets hot, he does do some crazy stuff," Goggin said. "If you drive the ball well you have some birdie chances and, if you don't, you struggle to break par."
