Amateur Paul Dunne eyeing history at St. Andrews

ST. ANDREWS, Scotland -- Not since Bobby Jones in 1930 has an amateur won The Open, and then along came Paul Dunne with a bogey-free performance Sunday that gave him a share of the 54-hole lead at 12 under.

Paul Dunne, the 22-year-old from Ireland, was impervious to everything around him and soaked up a day he won't soon forget in his round of 6-under 66 on Sunday. Louis Oosthuizen, the last player to lift the Claret Jug on the Old Course in 2010, also owns a share of the lead after making three birdies over his final five holes for a 67. Jason Day, who shot 67, is also in the mix, with a share of the 54-hole lead for the second straight major, and this time he doesn't have to worry about the vertigo symptoms he dealt with at the U.S. Open.

"It's surreal I'm leading The Open, but I can easily believe that I shot the three scores that I shot," Dunne said. "If we were playing an amateur event here, I wouldn't be too surprised by the scores I shot. It's just lucky that it happens to be in the biggest event in the world.

"Hopefully, I can do it again tomorrow. But whether I do or not, I'll survive either way."

Dunne and Oosthuizen will tee off at 2:30 p.m. local time (9:30 a.m. ET; final-round coverage begins on ESPN/WatchESPN at 6 a.m. ET).

Day (67) had a shot at the outright lead but missed a birdie putt on the 18th. The Aussie is set to start at 9:20 a.m. ET with Jordan Spieth, who is 1 shot back and aiming for his third straight major victory after winning the Masters and U.S. Open.

When Sunday's shootout at St. Andrews ended, 14 players were separated by 3 shots. Half of them were major champions.

Even for a place packed with centuries of history, this Open offered endless possibilities. Rarely has the Old Course been as easy as it was Sunday.

One day after raging wind off the Eden Estuary caused a 10-hour delay and forced a Monday finish, the flags were soaked from passing showers and limp from no wind. The leaderboards were loaded with birdies, and seven players had at least a share of the lead at some point in the third round. Marc Leishman flirted with a record-tying 63 until he made par on the closing hole. It still got him within 3 shots of the lead.

That's what made Dustin Johnson's collapse so shocking. With a 1-shot lead after powering his way around St. Andrews for 36 holes, he was the last player in the field to make a birdie, and that wasn't until the 15th hole. He followed with three straight bogeys for a 75 to fall 5 shots behind.

That might not seem impossible to make up, though having 17 players ahead of him makes it a tall order.

Padraig Harrington, a three-time major champion, revived his game with a 65 and is 2 shots behind. The nine players at 9-under 207 include Sergio Garcia, Justin Rose, Retief Goosen, Adam Scott and one other amateur -- Jordan Niebrugge of Oklahoma State, who shot a 67.

The Associated Press contributed to this report.