Jim Wholford, who had staked his spot in line more than a half hour before the 9 a.m. opening, headed upstairs with his 8-year-old son, Alex, to the "Steal Home Challenge."
A late-arriving Joe Marone walked through the entrance and directly over to the Negro Leagues exhibit.
Ken Coulter and his 15-year-old son, Ryan, set off straight for the batting cages.
And 24-year-old Philip Taylor had his eyes on the 27 memorabilia displays that made up "Collectors Showcase."
The show's billing held true. There was undeniably "something for all ages."
"It's definitely quite the experience," Coulter said. "All this stuff is pretty neat."
Perhaps nobody was more impressed by the scene than Mazeroski, the FanFest's co-spokesman along with current Pirates All-Star Jason Bay, who was with his team in Philadelphia on Friday.
"Boy, how things have changed in the last 35 years," Mazeroski said during a brief opening ceremony. "The last All-Star Game I was in, we just went in and played the game. ... This is just amazing. They've got everything here"
One of the many events included a question-and-answer session between the seven-time All-Star and fans on the second floor diamond to kick the day off at 9:30 a.m. Mazeroski spoke warmly of his days with Roberto Clemente, his historic home run to win the 1960 World Series, the Pirates retiring his No. 9 and his tearful speech after being inducted into the Hall of Fame in 2001.
"Something overwhelmed me and I couldn't help it," Mazeroski said, now smiling. "I even cry at commercials on television."
Still, he inevitably kept steering back to the present and the more than 40 interactive exhibits that surrounded him over 400,000 square feet of "baseball heaven."
"This is as big as it gets," he said. "I've never seen anything like this."
He then made his way over to the "Legends" area to sign autographs, where hundreds waited in line.
Marone was there with his black and white oversized Mazeroski baseball card that he won at an arcade some 40 years ago.
"If I can get him to sign my card, that will make my day," he said.
Others came prepared with backpacks and memorabilia ready to go for a cast of signers that also on Friday included Chuck Tanner, Steve Blass, Ron LeFlore, Jim Leyritz, Phil Niekro, Al Oliver, Dave Parker, Jim Rooker and Manny Sanguillen. And some, like Taylor, had designs on coming every day to add more and more signatures to their collection.
For now, though, he was adding more items to his collection after just purchasing a pair of Clemente and Willie Stargell All-Star figurines that could only be found at FanFest.
"A lot of the stuff is for the kids, but this stuff is great," Taylor said over the din of Wee Jams, a Pittsburgh oldies band playing nearby.
Across the gaping room, Alex Wholford sprinted across soft green carpet from third base to the plate in the "Steal Home Challenge." No records were set, but the smile he left with was good enough for his dad.
"It's been pretty cool," Wholford said. "For me, it's just about watching him have fun."
Same for Scott Baldi, who came with his 5-year-old son, Alex.
"It's so great for the kids," he said. "[Everything] definitely keeps them interested and that's all you can ask."
There are still tickets available for Saturday through Tuesday and can be purchased online at MLB.com or by phone at 1-888-FANFEST. The hours run from 9 a.m. to 8 p.m. ET through Monday and 9 a.m. to 7 p.m. ET on All-Star Tuesday. Daily tickets are $20 for adults and $15 for seniors, military personnel and children (3-12). They will be sold on a timed-entry basis, so fans must reserve their date and time.
David Briggs is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.