SAN DIEGO (REUTERS) - Perennial Major contender Louis Oosthuizen sank a monster eagle putt at the final hole to vault into a three-way tie for the lead after the third round at the US Open on Saturday (June 19).

The South African's downhill, 50-footer slammed into the middle of the flag and toppled in to add another layer of fascination to what already was shaping up to be a compelling final round on Sunday at Torrey Pines.

With a one-under 70, he joined Canadian surprise package Mackenzie Hughes (68) and steady American Russell Henley (71) at five-under 208.

But the three front runners did not have to look far over their shoulders to see heavyweights Rory McIlroy (67) and Bryson DeChambeau (68) waiting to pounce just two strokes behind.

Pre-championship favourite Jon Rahm (72), despite a double-bogey, is among a trio three behind.

Thirteen players in all are within four shots of the lead.

Oosthuizen, the 2010 British Open champion, has completed the career runner-up Grand Slam, and just last month was equal second behind Phil Mickelson at the PGA Championship.

Now he has another chance but knows it will take something special.

"There are a lot of great players up there that have a chance of winning this, and I just need to go out and play as good as I can tomorrow," he said.

Henley started the day tied for the lead with Richard Bland, and maintained at least a share of it the entire day.

"I'm 32, I don't know how many more good years I have of golf left," said the three-time PGA Tour winner. "I'm excited, and you always wonder what it would feel like or be like to be in contention." He will find out soon enough.

Hughes, meanwhile, vaulted into contention by holing a 35-foot bunker shot at the par-five 13th that prompted an enormous gallery roar that reverberated across the canyons to the rest of the course.

In uncharted territory, he did not even attempt to play down the situation.

"You get goosebumps thinking about it, so I know I'm going to be nervous tomorrow," he said. "I essentially played today around the lead all day. I think I was only ever a few back the entire day. I think it'll feel different tomorrow being in that last group, but you do the same things."

While Hughes surged, halfway co-leader Bland's fairy-tale run came to a screeching halt. The 48-year-old, who recently became the oldest winner on the European Tour, battled to a 77 that left him six behind.

McIlroy, seven years removed from the most recent of his four Major titles, could hardly ask for a better chance to end his drought.

"I'm trying to think of the last time where I really felt like I had a chance," said McIlroy, who had to go back to the 2018 British Open where he tied for second.

"I'm just excited for the opportunity to have a chance."

Defending champion DeChambeau, meanwhile, ignored a smattering of minor heckling to pound his way into contention with another bone-jarring performance of long driving.

He compiled his first-ever bogey-free round at an Open, picking up three birdies and coming ever so close to making a few more.

"You've got to be really patient out here at these Majors," he said. "It's something that is not easy to do. My first few goes at Majors, I was not successful or anywhere near successful, and I feel like I'm starting to understand Major championship golf and how to play it and how to go about managing my game, my attitude and just my patience level.

"If I can continue to do that tomorrow, I think I'll have a good chance."

Mickelson, a record six-time US Open runner-up, saw his bid to complete the career Grand Slam disappear for another year after a sloppy five-over 76 left him at seven over.

Playing a month after becoming golf's oldest Major winner at 50 by claiming the PGA Championship, Mickelson could not produce the same magic in his home town.