By Lyle Fitzsimmons

I’ve interviewed Holly Holm several times.

Heck, I’ve even been punched in the mouth by a woman who was training to fight her.

So I felt like I had a vested interest in watching her on center stage in the wee hours of Sunday morning, and I confess to being as happy with her result as I can remember being with any in recent memory.

And while it wasn’t quite boxing, the pure shock of the result made me remember the few moments in my ring-observing career where my mouth hung open in disbelief over what I’d seen.

There are upsets – like Rigondeaux-Donaire or Cotto-Martinez – and then there are jaw-droppers.

In honor of Ms. Holm’s triumph, here’s a look at some of the ones I still don’t believe.

Iran Barkley TKO 3 Thomas Hearns – June 6, 1988

I’m among the world’s biggest “Hitman” fans, so by the time June 1988 arrived I was in a good place.

Marvin and Ray had been off the radar for a year, which left the middleweight domain – finally – under the thumb of Hearns, who’d won/defended titles in a three-year stretch since losing “The War.”

He strafed Barkley to the head and ripped him to the body, and I still recall turning to my girlfriend at the end of the second round and suggesting it was as good as I’d ever seen him look.

Needless to say, my tune soon changed. And come to think of it, she didn’t make it another year either.

Buster Douglas KO 10 Mike Tyson – Feb. 11, 1990

If the caged result from Australia reminded me specifically of any fight, it was this one.

Tyson, like Ronda Rousey, was the darling of the “baddest on the planet” set, and his trip to Tokyo – like Ronda’s to Melbourne – was the next step in transforming the menace into a global brand.

And unlike each of the other upsets, this was no one-punch phenomenon.

Douglas, like Holm, won nearly every moment of competition before finally putting his prohibitively favored foe out of his misery. It remains the standard to which every new upset is compared.

George Foreman KO 10 Michael Moorer – Nov. 5, 1994

It may be now – as I pass the halfway point of age 46 – that I fully appreciate what a 45-year-old did.

Though he’d been competitive and brave against Evander Holyfield three years earlier, Foreman had done precisely nothing in the intervening time – including losing to Tommy Morrison – to make anyone believe magic was about to occur.

He was thrashed for nine rounds, beaten into a puffy mess and was about nine minutes from realizing the mistake he’d made in tangling with an unbeaten and talented foe who was 19 years younger.

Until he prompted Jim Lampley into a call that still raises the hair on my arms. “It happened,” indeed.

Antonio Tarver TKO 2 Roy Jones Jr. – May 15, 2004

I’ll have the argument with anyone who cares to entertain it. In the years in which I’ve been a big fan, a prime Jones is the best I’ve ever seen. He was blindingly fast. He had one-punch KO power.

He’d beaten Tarver six months earlier, and looked likely to better his own initial result in the rematch when unfettered with the struggle to drop down from heavyweight to 175.

When Tarver shot his mouth off during Jay Nady’s instructions, I was sure he was doomed. And after Jones appeared the boss through the first three minutes, I was perhaps three times more certain.

To this day, it’s the left hand that took him out that makes me realize anyone can lose.

Even “Superman.”

Juan Manuel Marquez KO 6 Manny Pacquiao – Dec. 8, 2012

I think he won the first one. And I’m sure he won the third one.

That said, had you asked me about Marquez’s chances after the fifth round of their fourth fight, I’d have put them right up there with any one of Wlad Klitschko’s recent heavyweight challengers.

His nose looked broken. His stamina looked questionable. But his will was surely still there.

And while I’m very happy that Manny ultimately got up and resumed his winning ways a few months later, I swear for a few seconds I’d seen a man killed with a single punch.

*  *  *  *  *  *  *  *  *  *

This week’s title-fight schedule:

SATURDAY

IBF bantamweight title -- Las Vegas, Nevada

Randy Caballero (champion/No. 16 IWBR) vs. Lee Haskins (interim/No. 7 IWBR)

Caballero (22-0, 13 KO): First title defense; Second fight in Las Vegas (1-0, 0 KO)

Haskins (32-3, 14 KO): First title fight; Fifth fight outside the United Kingdom (3-1, 1 KO)

Fitzbitz says: The champion has youth and a pristine record, but the Englishman appears to have righted the ship since a 2012 stumble and should take the youngster into deep water. Haskins by decision

WBA lightweight title -- Manchester, United Kingdom

Darleys Perez (champion/No. 15 IWBR) vs. Anthony Crolla (No. 9 WBC/No. 12 IWBR)

Perez (32-1-1, 20 KO): First title defense; Eleventh fight outside Colombia (8-1-1, 4 KO)

Crolla (29-4-3, 11 KO): Second title fight (0-0-1); Drew with Perez on July 18

Fitzbitz says: There are plenty of people who’ll testify that Crolla was better the first time around, and it says here that they’ll be right if they sat it again. Only this time it’ll be official. Crolla by decision

WBC middleweight title -- Las Vegas, Nevada

Miguel Cotto (champion/No. 1 IWBR - 154) vs. Saul Alvarez (No. 1 WBC/No. 2 IWBR - 154)

Cotto (40-4, 33 KO): Second title defense; Held titles at 140, 147 and 154 pounds

Alvarez (45-1-1, 32 KO): Ninth title fight (7-1); Seventh fight in Las Vegas (5-1, 3 KO)

Fitzbitz says: Cotto’s got the resume and the skill set. Canelo’s got the youth and the size. About as even a high-profile fight as there’s been lately, but the 10-year age gap breaks the tie. Alvarez by decision

WBC super featherweight title -- Las Vegas, Nevada

Takashi Miura (champion/No. 2 IWBR) vs. Francisco Vargas (No. 1 WBC/No. 4 IWBR)

Miura (29-2-2, 22 KO): Fifth title defense; Second fight outside Japan (1-0, 0 KO)

Vargas (22-0-1, 16 KO): First title fight; Fifth fight in Las Vegas (4-0, 2 KO)

Fitzbitz says: Miura has stopped four foes in five title fights and appears to have gotten better as champion, but it feels like Vargas has done well against better names. Vargas in 8

WBO super middleweight title -- Hannover, Germany

Arthur Abraham (champion/No. 2 IWBR) vs. Martin Murray (No. 10 WBO/No. 12 IWBR)

Abraham (43-4, 29 KO): Fifth title defense; Won 11 of 12 fights since 1-3 slump in 2010-11

Murray (32-2-1, 15 KO): Fourth title fight (0-2-1); Undefeated above 160 pounds (23-0, 11 KO)

Fitzbitz says: Abraham has been successful since a detour in the Super Six tournament a few years back, but hardly unbeatable. Murray has shown enough in near-misses to get over here. Murray by decision

Last week’s picks: None

2015 picks record: 75-21 (78.1 percent)

Overall picks record: 714-244 (74.5 percent)

NOTE: Fights previewed are only those involving a sanctioning body's full-fledged title-holder – no interim, diamond, silver, etc. Fights for WBA "world championships" are only included if no "super champion" exists in the weight class.

Lyle Fitzsimmons has covered professional boxing since 1995 and written a weekly column for Boxing Scene since 2008. He is a full voting member of the Boxing Writers Association of America. Reach him at fitzbitz@msn.com or follow him on Twitter – @fitzbitz.