I have seen a depressingly low number of sporting events in person. And of those, none made any headlines. The biggest I saw live was the 2016 fall Talladega Nascar Cup race, but nothing newsworthy happened that day.
That said, I'll have to go online for this one.
It's the 2002 Delphi Indy 300. Sam Hornish's 2006 Indy 500 win is my favorite single race (and in my biased opinion, sporting event) of all time, but in my opinion, the greatest auto race ever was the 2002 running of the Indy Racing League at Chicagoland.
A very, very unpopular opinion.
I know.
But the ending of the race is one that I still can't get over after watching it more times than I can count. The racing is a perfect stalemate lap after lap at speeds that even today that prefer not to think about. It doesn't hurt that the result was Hornish winning by the closest margin of victory I've ever seen recorded outside of drag racing. It's a timeless race that still holds up to this day.
CART fans would string me up for saying that.
But I'm an IRL fan.

thing1 : I think you will like this one. 

It was during a wrestlamania Seth Rollins was fighting Randy Orton  and Seth has Randy down and runs going for his move a curb stomp as soon as he foot touches Randy's head. Randy shoots up, throwing Seth at least six feet in the air and gives him the most insane RKO I have ever seen. I remember jumping out of my seat, and spilling a lot of things.

Droog : I remember that. I actually watched that WrestleMania. But, I haven't watched WWE since the PPV after the WrestleMania where Undertaker lost to Brock Lesnar

Greatest moments I have seen in sports are when there are choke cities to the max. Warriors 73-9 was dope but the Bulls 72-10 had a better ring to it as the Dubs choked on a 3-1 lead. Who can ever forget the Falcons 28-3 lead collapsing in the Super Bowl? They will never live that one down. HA HA HA!!!

Probably the greatest thing I've seen on TV was when Sweden and Germany were playing a World Cup qualifier in Germany back in 2012. Germany was completely dominating the game to where around 55 minutes in the standing was 4-0 to Germany. Sweden would then go on to turn the match around to a final standing of 4-4 scoring the last goal during added time. I don't remember much else from the world cup that year but that turn around was a legendary sight. Especially after most people had already changed channels and were thinking it was going to be one of the greatest losses ever seen in a qualifier. Seeing Zlatan score 4 goals against England including his infamous bicycle kick goal (which is arguably up there as one of the greatest goals ever scored in the history of football) was pretty legendary as well.

Pretty much every World Championship Final that Sweden has won in ice hockey could make it on this list for me as well. It's such an intense sport that you're bound to find great moments in every match. Can't say I've seen anything too noteworthy in person from any sport. The most noteworthy thing I saw was a 3-0 win by my city's hockey team against one of the series leaders back when I was in primary school. Which was noteworthy because our team were playing awful that year and was on a huge loss streak. Not exactly a legendary moment but kind of noteworthy I would say.

I've never been to a great sport moment in person, but I've seen a LOT of great sports moments on TV live for football. Like watching Packers coming back and throwing the hail mary on Detroit to watching the Patriots come back against the Falcons on the last Super Bowl.