The most memorable moment in a revealing new documentary about Tiger Woods captures him collapsing to the ground.

I'm not referring to the legendary golfer dropping to his knees during a 2013 tournament, soldiering on despite a severe back injury. It's a snippet from a home movie from his high school sweetheart, Dina Parr.

The grainy footage shows a teenager dancing with friends in a Hawaiian shirt, showing off his chest hair like it had just grown in the previous week, then writhing on the floor as he plays air saxophone, enthusiasm plastered all over his face.

"Tiger," which debuts 8 p.m. Sunday on HBO and concludes next weekend at the same time, is largely about how that boyish smile changed into a plastic grin, a sign of fierceness that helped make him a once-in-a-lifetime athlete — and one of the loneliest figures in sports history.

Directors Matthew Heineman and Matthew Hamachek dedicate the first installment to Woods' relationship with his parents, a strict mother and a controlling father who believed his son would be bigger than Jesus. They convinced Woods to terminate his three-year relationship with Parr in a Dear John letter that's 64 times more vicious than ghosting.

Around that time, Woods started collecting Amateur Championship titles and losing his ability to boogie to the beat.

The second installment, which will steal most of the headlines, follows the champ as he trades the dance floor for Las Vegas, where he systematically goes through sexcapades the way mere mortals drop quarters in a slot machine.

Only a couple of professional golfers are included in interviews, leaving plenty of time for those who knew Woods off the course. Rachel Uchitel, his most famous mistress, details their longtime affair. Former National Enquirer editor Nick Boulton takes so much delight in recounting how his tabloid exposed Woods' extramarital outings you'd think he just killed Osama bin Laden.

The filmmakers aren't nearly as zealous in tracking Woods' downfall. To them, he's a victim of overbearing parents, pushy paparazzi and a determination to be the best, no matter how much damage it does to his psyche or his body.

Not that Woods is a saint.

There's extensive footage of him being arrested for driving under the influence of prescribed drugs. His former caddie Steve Williams shares how he was given the cold shoulder, despite the fact that he had served as best man at Woods' wedding to Elin Nordegren.

Ex-wife Nordegren isn't among the talking heads in the two-part film, nor is his most famous ex-lover, skier Lindsey Vonn. Woods himself appears to have only given the filmmakers a few moments of his time. You would think that would put him at a disadvantage. But Woods has never been very keen on self-reflection. His canned responses to introspective questions over the years have often been his worst enemy.

But the film ends with Woods entering a third chapter, one in which he seems to have come to terms with his demons and rediscovered his love for the game.

In the final moments of "Tiger," there's footage of him joking around with competitor Kevin Na at a recent tournament. As he gives Na a fist bump, a smile appears on Woods' face.

It sure looks a lot like the one from that dance party.

Neal Justin • 612-673-7431 • Twitter: @nealjustin