O'Connor: The humbling of Brooks Koepka at the PGA Championship

Golf was one of the last trash talk-free zones in American sports until Brooks Koepka swaggered his way to the first tee. He was never going to be Conor McGregor, but emboldened by his superhero arms and unbending belief in himself, Koepka sometimes said things that would make a pay-per-view promoter proud.

Like on Saturday night, when Koepka was asked how he felt about starting the final round of the PGA Championship chasing his friend Dustin Johnson, a year after Johnson nearly ran him down at Bethpage. A two-time defending champion of this event and a four-time major winner, Koepka decided it was time to show Johnson his trophy case.

"I mean, I like my chances," Koepka said. "When I've been in this position before, I've capitalized. I don't know, he's only won one."

With friends like that, who needs columnists?

Hey, most of us bought what Koepka was selling at TPC Harding Park in San Francisco. He had an established history of walking the talk, making it easy to imagine his 2-shot deficit being erased a half-dozen holes into the round.

But a strange thing happened to Koepka on his way to making history as the first three-peat winner of any major championship in more than six decades. He started playing like all the one-hit wonders (in addition to Johnson) he referenced more than once in his Saturday news conference. On a day when the 23-year-old winner, Collin Morikawa, shot 64 and emerged from a surreal seven-way tie for the lead on the back nine, Koepka shot a 4-over 74, which beat exactly one player (Jim Herman) out of the 78 he was competing against.

One out of 78, after taking an unnecessary dig at a former U.S. Open champ who deserved better.

Rory McIlroy, perhaps the tour's most thoughtful player, said that he was taken aback by the comment, and that Koepka should have at least picked his targets more carefully. "Sort of hard to knock a guy that's got 21 wins on the PGA Tour," McIlroy said of Johnson, "which is three times what Brooks has."

Rory's might have been the best iron shot on a memorable pandemic day that delivered a brand of golf that would have inspired fans to roar all round, had they been allowed on the course. Who could possibly believe there would be seven players tied at 10 under deep into the round, with none of them being named Brooks Koepka?

But sure enough, while golfers up and down the leaderboard were busy shooting in the mid-60s, the presumed favorite was looking more like one of the regular 16 handicappers at this city-owned course. Playing with Paul Casey, who would shoot 66 and finish in a tie for second with Johnson, Koepka admitted he was reduced to a nonentity after closing his front nine with three consecutive bogeys.

"I was just there to cheer Paul on," he said.

Built for NFL contact, Koepka became the incredible shrinking man. CBS cameras stopped showing him altogether, the ultimate indignity for a contender who had called out another man.

"Every time I hit it in the rough today," Koepka said, "I got probably the worst lie I've had all week. ... Hey, wasn't meant to be. Three in a row, you're not really supposed to do two in a row looking at history, but that's all right. Got two more [majors] the rest of the season and we'll figure it out from there."

On any other Sunday gone awry, Koepka would have earned the benefit of the doubt. He had struggled with a significant knee injury before nearly winning in Memphis, Tennessee, last week. This PGA Championship could have been a throwaway for him, a bridge back to full health and, perhaps, pushing his chance at a fifth major victory to September's U.S. Open or November's Masters.

But he said what he said Saturday and there should be consequences for failing to honor his words. Not that this will be the last time Koepka talks more like a mixed martial arts fighter than a golfer. The man who claimed majors are easier to win than minors, because so many players in the field don't have his skill and poise under pressure, has a long history of blustering his way from tee to green.

Koepka prides himself on being an athlete first, rather than the prototypical golf nerd, and on being a singular force on tour. "I'm not close with any of the guys out here," he recently told Golfweek during an interview in which he said his reported friendship with Johnson was "blown out of proportion."

Koepka has denied reports that he had an altercation with Johnson after the 2018 Ryder Cup, but there is no disputing the fact that they were once roommates and worked out together at a gym in Jupiter, Florida. Johnson was once the more prominent player. Maybe after beating Johnson in two Long Island, New York, majors -- at Shinnecock in 2018 and at Bethpage in 2019 -- Koepka figured he could flex his muscles at Harding Park and remind his friend/frenemy/former friend that he'll be the one doing the overshadowing going forward.

In the end Sunday, Koepka lucked out when Johnson's 68 wasn't good enough to claim his second major title. But this wasn't about Johnson as much as it was about the guy who shot 74, the guy who looked completely washed out on his last hole while he finished off his sixth bogey.

Brooks Koepka was finally humbled. And that was by far the biggest upset of the day.