It was Mayberry's first career hit. He also doubled to finish 2-for-3.
"It was incredibly exciting, more than I ever imagined," Mayberry said.
And it happened at the new Yankee Stadium, too.
"I think you can't draw it up any better than this," Mayberry said. "In my wildest dreams, that definitely didn't happen."
Mayberry hit a 1-1 fastball from Pettitte over the left-field wall to give the Phillies a 4-1 lead.
The Phillies gave Mayberry the silent treatment as he entered the dugout, but he caught on quickly before his teammates finally walked over to congratulate him.
"Andy gave us what we needed, he made one mistake really to John Mayberry today," Yankees manager Joe Girardi said. "And for that young man to get his first hit in Yankee Stadium off a great left-hander, I'm sure that was pretty exciting for him."
Mayberry got the home run ball.
Interestingly, Mayberry's father, John Mayberry Sr., hit his last career homer at the old Yankee Stadium on Aug. 8, 1982. Mayberry Sr. hit 255 home runs in 15 seasons in the big leagues. He finished second in the American League MVP voting with the Kansas City Royals in 1975, and earned AL All-Star honors with the Royals in '73 and '74.
He and his wife were in attendance Saturday.
FOX actually identified the wrong man as Mayberry Sr. for about an inning before they finally found him in the stands.
"I got a kick out of that," the rookie said.
He got an even bigger kick out of the homer.
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.