In between his turns at the plate, Zagoras exchanged comments with the Hall of Famer and took a picture with the former catcher.
"I just told him I'm a diehard Yankees fan," Zagoras said. "I love the Yankees, and I look up to guys like him."
During the clinic, Berra asked Zagoras if he played baseball. But once he was off the diamond, it took Zagoras a minute to remember which team he played for -- Long Island City.
"He's overwhelmed," his mom, Bessie, said, laughing. "That's what Yogi does to you."
Berra helped kick off the five-day FanFest event Friday morning, and fans surrounded the entrance as he and Tom Snowberger, senior vice president for DHL Express, cut the yellow ribbon that represented the official start to the festivities.
Once the oversized yellow scissors had done their job, the FanFest space filled with the sounds of drums, confetti flew and mascots from Major League teams danced and welcomed fans.
As a golf cart brought Berra to various spots around the event, including a live radio broadcast, a trail of people followed behind. Berra, a spokesman for this year's FanFest, along with Derek Jeter, said he's impressed at how much the All-Star celebration has grown.
"They're doing better now than when we started playing," Berra told WFAN Sports Radio. "We just went at the time we went to play, and that was it. Play the All-Star Game and go home. I never thought it would come this far. It's a great thing."
The displays and attractions spread across 450,000 square feet, and while it's not the largest FanFest on record in terms of size, MLB director of special events Jackie Secaira-Cotto said the New York FanFest is expected to draw the biggest crowd.
Fans who stood in line before the doors opened at 8:30 a.m. ET for the ribbon-cutting ceremony were not disappointed. They spread to every part of the event. Some ran straight to the video batting cages. Others posed for their own trading card in their favorite team's uniform.
Zagoras said one of his highlights was seeing the Commissioner's Trophy -- given to the World Series champion each year -- at the Tiffany & Co. display. He came with his mom, aunt, cousins and friends, and he said he had been anxious to get there since Thursday.
"We just knew we were going to come here, and we're all big baseball fans, my whole family," he said. "Just to come here and see all this, it's the best thing I've ever seen in my life.
"I've been to Cooperstown, and this is better than Cooperstown, because at Cooperstown I know a lot of the names, but there's way more things here."
Cooperstown probably wouldn't crown a bear the champion of a home run derby, either, but T.C. of the Minnesota Twins took the top spot in the first round of the State Farm Mascot Home Run Derby.
That was good news for eight-year-old Francely Mejia, a member of the Boys & Girls Club of America from Manhattan, who was partnered with the winning mascot. T.C. hoisted her on his shoulders after the victory, as Mejia giggled and smiled. Both will get the chance to come back and win Monday in the championship round.
"It was a lot of fun because my mascot hit a lot of home runs," Mejia said. "I hope he does it again Monday so I can get the trophy."
While the mascots battled it out for derby pride downstairs, Russell Sands of Mount Sinai, N.Y., stood in line upstairs for the chance to meet Bob Watson, Fred Lynn and Steve Sax, a few of the MLB Legends on hand to sign autographs.
Sands waited in the snaking line for an hour, but said it was worth it.
"They're actually talking to people, shaking hands," he said. "You get to get a couple of moments just to say something. And these guys are no slacks, they're all great players."
Sands brought his 13-year-old nephew to FanFest and said the experience gave both of them different aspects to enjoy. The five-day celebration will culminate Tuesday night, and Sands will be in attendance to watch the final All-Star Game to be played at Yankee Stadium before it closes at the end of the season.
"I think it's going to be a very nostalgic event," Sands said. "This is going to be, for a lot of people, the last time they'll ever put foot in Yankee Stadium.
"The whole celebration, the whole atmosphere, I think it's finally going to hit a lot of people, and I think they're going to make that presence known."