For the better part of three days it was difficult for even the most dedicated follower of golf to figure out just what was going on in a U.S. Open turned upside down at Oakmont Country Club.

Jason Day needed most of that time to figure things out himself.

The world's best player tapped in for a routine par on his final hole Saturday as the shadows lengthened over Oakmont, and it was finally time to start trying to make sense of this Open. He was in the clubhouse with three full rounds under his belt, which for many on this day was accomplishment enough.

Still, Day had his sights set on something more.

Something like a U.S. Open trophy to add to his ever growing collection of golf hardware.

"All I want to do is try to win the tournament," Day said. "I think I've given myself an opportunity getting there."

That might sound a bit optimistic, given that Day was six shots behind leader Shane Lowry and Oakmont is showing signs of firming up and getting tougher. The reality is there probably won't be four birdies and an eagle out there for Day like he made on his way to a 4-under 66 that vaulted him up the leaderboard in the third round.

But if there's anything the other players ahead of him must keep in mind Sunday is that Day understands how to win. Understands it so well that he did it seven times in the last calendar year, including the PGA Championship for his first major title.

Add in the fact that he has got three rounds in the bank and almost everyone ahead of him still must go out Sunday morning to complete their third rounds, and suddenly the scenario doesn't seem so improbable at all.

"We'll see how those guys go in the morning and, hopefully, I'll be there," Day said.

Bookies in Las Vegas give Day a fighting chance, offering 12-1 odds on him winning his first Open. He was one of the early favorites when the week began, before struggling to an opening 76 and needing to finish his second round strong just to make the cut.

He's still got an uphill slog to win, but this is the U.S. Open and this is Oakmont. With trouble lurking everywhere, no lead is really ever safe and none of the seven players above him on the leaderboard have ever won a major title.

Day had barely just signed his scorecard and already he had that digested and analyzed.

"Depends how they look at it," he said. "If they want to go out there and they think they're ready to win a major, then it's obviously going to be tougher because they're going to be focused and ready."

Day's round got the attention of Lowry, who was well on his way to a fine round himself before being forced to stop by darkness after 14 holes. Lowry has to get up early Sunday and finish his round before offering any claim to a final-round lead.

"Let's not get ahead of ourselves," the Irish player said. "These are the best golfers in the world behind me, Dustin (Johnson) and Jason."

Day had talked earlier in the week about how he thought about quitting the game five years ago because it was no fun and he didn't seem to be getting any better. But his confidence grew and he began to find an inner peace about the game that culminated with him winning four times in the last half of 2015 and another three so far this year.

He seems to thrive under stress, and there is nothing more stressful than Sunday at the Open when the pins are put in precarious positions and the greens run faster than they have all week.

Day wants those conditions on Sunday, practically begging the USGA to set the course up as hard as possible.

"I just want it to play hard and fast and I think the harder the better, like a normal U.S. Open Sunday should be," he said. "I think it would be fun for everyone. Even though it is hard and stressful, I just enjoy those times."

The USGA is likely to oblige, which means par will be a good score. And if the players ahead of him start slipping back, Day may find something he enjoys even more.

Like holding an Open trophy above his head.

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Tim Dahlberg is a national sports columnist for The Associated Press. Write to him at tdahlberg@ap.org or http://twitter.com/timdahlberg