Billy Crystal — from Sha Na Na to Yankee Stadium

NEW YORK — Billy Crystal remembers a show in Baltimore, around 1975, when he opened for the ’50s revival act Sha Na Na.

He was an unknown comic at the time, an unknown who happened to look exactly like one of Sha Na Na’s lead singers, Johnny Contardo.

“I’m introduced and I have no billing,” Crystal says during a recent interview. “‘Please welcome another star of our show and an up-and-coming new comic ...’ That was the ’70s. Whenever you heard ‘up-and-coming new comic,’ it was like ‘Ugh.’

“When I hit the stage they thought I was Johnny playing a guy named Billy Crystal and they booed and they hissed and so forth. And I started getting in their face, in a funny way. And I finished my set and I got a standing ovation after I walked off. And Johnny got a T-shirt that he would wear and it said, ‘No, I’m not Billy Crystal.”’

It’s been a long time since Billy Crystal has been mistaken for anyone else.

At 65, he has the same round face, scrappy New York accent and rubbery grin known to fans of “Analyze This,” “When Harry Met Sally ...” and all those Oscar telecasts. Seated in his publicist’s office, sipping coffee from a paper Starbucks cup, he looks at least a decade younger than his age and is working at the same pace — constant — that he’s kept up for much of his life.

He’s set to star in a film comedy directed by Frank Oz and this fall will return to Broadway with his one-man show about his childhood and his father, “700 Sundays.” His whole life is on record for his current project, the memoir “Still Foolin’ ’Em,” which set off a million-dollar bidding war among publishers last spring that was finally won by Henry Holt and Company.

Turning 65 was all the inspiration he needed.

“All of my really dear friends who are the same age are pretty much saying the same thing, which is basically, ‘Wow. Jeez. This is really happening,”’ he says. “You go through stages — first day of school, ‘It’s a bar mitzvah,’ ‘a wedding.’ ‘You know who died?”’

Crystal is both a typical baby boomer, baseball fan and political liberal who brags about his grandchildren and can’t believe that he’s a grandfather and a VIP who seems to have lived out every childhood fantasy — a star of movies, television and the stage, befriended by Muhammad Ali and Mickey Mantle, adored by Sophia Loren. During one Oscar show, Jack Nicholson and Warren Beatty stopped by his dressing room to compliment him. Beatty and Bill Clinton turned up backstage after a performance of “700 Sundays.”

He has not only palled around with Mantle, Yogi Berra and other New York Yankees, he even got to play for them.

“In 2007, I was in Costa Rica for Christmas vacation and could feel my birthday looming,” Crystal writes in his memoir. “I was anxious about turning 60 — it felt like a huge number. Derek Jeter happened to be at our hotel.”

Jeter “happened” to be there, and also happened to be a longtime friend who asked Crystal to make a birthday wish.

On March 13, 2008, Crystal was allowed an at-bat during a Yankees exhibition game.

“Dreams have come true for me in so many different ways that’s it’s almost astounding,” he says. “As I was writing these things, other people reacted to them — I’ve lived through them, but other people say, ‘Do you realize how many great things have happened?”’

He has had disappointments — minor, major and profound. Joe DiMaggio once punched him in the stomach (Crystal, hosting a tribute at Yankee Stadium for Mantle, had failed to introduce DiMaggio as “the greatest living” baseball player). He was scheduled to appear on the debut broadcast of “Saturday Night Live,” but his segment was cut. The 1992 film “Mr. Saturday Night,” which Crystal directed and starred in, was a critical and commercial letdown that kicked off a dry spell and made Crystal wonder if his movie career was over.

But the real wound was sustained at age 15 when his father died of a heart attack. Jack Crystal was a jazz promoter and producer, and his son’s first audience.

“That’s how you start,” Billy Crystal says, “making your parents laugh. And he was a really great mentor in looking at these really great comedians on television and saying, ‘Watch Laurel and Hardy and not The Three Stooges.’ ‘You can stay up late, even though it’s a school night.’ Then you can watch Ernie Kovacs and stay up for Jack Paar because Jonathan Winters is on.”

With the 50th anniversary of his father’s death approaching, Crystal decided it was a good time for another run, likely the last, of “700 Sundays.”

“I love the energy of Broadway and I thought this was the way to commemorate it (his father’s death) and then put the show to rest,” he says. “I see the thread (in life) as I always end up returning to the stage, to get up in front of people and make them laugh and make them look at themselves and make them nod their heads and go, ‘Oh, that’s me, too.”’