In 29 years of calling baseball games on television and radio, Dave O’Brien has seen just about everything.

But the moment he witnessed -- and called so superbly -- on Oct. 13, 2013, is the one he cherishes most.

And while the 56-year-old O’Brien likely has many years left in the booth, it’s hard to imagine anything will ever top his astonishment over what David Ortiz did on that Sunday night in Game 2 of the American League Championship Series against the Tigers.

It’s one thing to have the opportunity to call such an iconic moment. It’s another to rise up to that moment with a call that will always be remembered and likely replayed for generations to come.

With the Red Sox down, 5-1, with two outs in the bottom of the eighth inning and in danger of falling behind in the series, 2-0, Big Papi hit a game-tying grand slam into Boston’s bullpen against Detroit reliever Joaquin Benoit.

Yes, there was Torii Hunter’s dramatic sprawl over the wall in pursuit of the ball, and the bullpen cop who raised his hands in triumph, but the story was Ortiz coming through yet again when he was needed most.

“When I go back to it, I still think the hair on my arm stands up, because what he did in that moment is just so astonishing,” O’Brien said. “It still is to this day. I don’t think I’ll ever feel quite like that calling a moment in my career.”

Here is what Red Sox fans heard from O’Brien in that moment:

“The big right-hander, Benoit, delivers. Swing and a high deep drive into right field, that one scalded to right, Hunter on the move, racing back, it’s over his head, it’s gone, it’s into the bullpen, this game is tied. This game is tied! David Ortiz! David Ortiz! David Ortiz!”

The excitement in O’Brien’s voice built as the ball was in flight. You could almost feel his heart racing as he made the call, capped perfectly when he said Ortiz’s name three times at the end.

What compelled the repetition?

“I don’t know. That’s not something you can ever really think about,” O’Brien said. “With David, I guess there’s the preparation somewhere in your head -- he could do something you’ve never seen before, something absolutely ridiculous, because he’s David Ortiz.

“I just thought, for emphasis, once, twice, three times. It’s almost like, just in case you didn’t get it, that was David Ortiz. That was David Ortiz. How many times has he done this? I guess that’s what came into my head. This guy does this all the time.

“You don’t get many of those opportunities in a career, and you hope you do them justice -- you really do -- at the end of the day. The electricity of the moment -- if that comes through -- if the sensation that you felt the moment you witnessed it is still there years later listening to the description of it, then I think it was effective.”

Adding to the magnitude of the hit by Ortiz and the call by O’Brien is that it sparked the Red Sox to a World Series championship.

“What anyone will say in that position as a broadcaster, [is] you want to capture the tone of the moment,” O’Brien said. “I think I’m probably most proud of that. … If the Red Sox don’t win that game, I think they lose that series, because they go down 0-2 heading to Detroit to face [Justin] Verlander.

“I don’t think anyone rallies to win that series, let alone the World Series. What [Ortiz] did was he saved the whole season. He certainly saved October and put the Red Sox in position to win another championship. I hope I was able to capture the tone and the setting well with that.”

The moments that Ortiz provided for O’Brien and many other broadcasters through the years were off the charts.

But that grand slam against the Tigers probably defined Ortiz’s career the best. Down four runs with four outs to go and a grand slam to tie it. Who does that?

“I will also say that’s what makes David an extraordinary icon, is because it wasn’t just a two-run double,” O’Brien said. “It was the whole enchilada. That’s really what I hope came through -- the amazement that that’s what he did.

“He’s always going to be at another level. He’s the greatest clutch athlete I ever saw in any sport, including Larry Bird or Tom Brady or anybody else. I just think that hitting the baseball is the most difficult thing to do in sports. For him to do that and accomplish those feats, to this day, it blows me away and blows us all away.”