England's Lee Westwood continued to roll back the years as he sought an overdue maiden major title in the 148th Open at Royal Portrush.
Westwood extended his own unwanted record of most top-three finishes in majors without a victory to nine when he was joint second in the 2016 Masters and also let slip a two-shot lead after 54 holes in the 2013 Open at Muirfield.
The former world number one was not eligible for either the Masters or US Open this season and missed the cut in the US PGA Championship, but his 25th consecutive appearance in the Open was turning into a wonderful opportunity to become the oldest first-time major winner in history.
The 46-year-old began the day a shot off the lead but made the ideal start with a hat-trick of birdies from the second to briefly claim the outright lead, only for playing partner Tommy Fleetwood and overnight leaders JB Holmes and Shane Lowry to quickly take advantage of benign conditions.
Fleetwood birdied the first and almost holed his approach to the fifth for an eagle, while Lowry picked up shots on the third and fifth and Holmes recorded gains on the second and third.
At 10 under par the leading quartet were three shots clear of clubhouse leader Danny Willett, the former Masters champion carding a bogey-free 65 to surge through the field.
"Today was pretty superb really," Willett said. "Ball-striking was spot on and we gave ourselves a lot of chances. The wind is dying down now and it would be nice to see it pick up again but that's links golf.
"If you play well and get in the last groups you should have the best weather, but you can see the leaders potentially getting that bit further away."
Defending champion Francesco Molinari had made the cut with nothing to spare and was in the second group out on Saturday, the Italian carding a 72 to finish two over.
"Obviously I would have liked to have a better defence of my title but at the same time you realise that you don't have the trophy but your name is still going to be on it," Molinari said.
"So it's bittersweet for now, that's all I can think. It's not easy, obviously, especially the first time and having played well in other majors this year, obviously you come in with the high expectations.
"But you've seen it with Rory (McIlroy) and other guys. Golf is a funny game so even if you're playing well, the mental side is still the biggest priority."
With Molinari surrendering his hold on the Claret Jug he would love nothing more than close friend Fleetwood, with whom he struck up such a devastating partnership at last year's Ryder Cup, to break his major drought.
"It would make a good story for you guys to have the two of us, one next to each other, on the Claret Jug," added Molinari.
"I'll cheer him on and hopefully he can get it done. There's still a long way but he's there with a chance. If it's not this week, I think it's coming pretty soon."