Jordan Spieth clinically moved closer to Open Championship glory on Saturday, stretching his lead over Matt Kuchar to three strokes and pulling clear of the rest of the field as Branden Grace made history in the third round at Royal Birkdale.
Following 31 scores of 63 in men's majors, Grace became the first man to go lower, shooting an eight-under 62 to etch his name into the record books.
The South African's stunning performance lifted him into a share of fifth at four under alongside Hideki Matsuyama (66), one behind the third-placed duo of Austin Connelly (66) and Brooks Koepka (68).
Yet Spieth, who has been at the top of the leaderboard since the opening day, was able to reach 11 under for the tournament courtesy of a faultless 65.
After holing a lengthy birdie putt on the 18th and seeing Kuchar (66) miss from much closer, Spieth will go into Sunday's final round with a wonderful chance of adding the Claret Jug to the Masters and U.S. Open titles he claimed in 2015.
A combination of softened greens and still conditions - in total contrast to the gusts of Friday - led to plentiful birdie opportunities during round three.
Spieth, who will celebrate his 24th birthday next week, and Kuchar each turned in 31 to open up a healthy cushion over the rest of the field.
When Kuchar made back-to-back gains on 14 and 15, his partner in the final group needed to hole a clutch birdie putt at the latter hole to keep sole possession of the lead.
Spieth was up to the task, though, and there was a two-shot swing on the 16th, Kuchar making double bogey after finding a bunker off the tee and then taking three putts.
The 39-year-old got back to within two of Spieth by getting up and down from a greenside bunker at the 17th, something the leader was unable to do.
Kuchar then bettered his rival's approach to the last. However, Spieth's uncanny knack of draining key putts came to the fore once more and Kuchar then failed with his own birdie try in a dramatic conclusion to the day.
Koepka mixed six birdies with four bogeys in an inconsistent round, while Connelly - the world number 524 - benefited from a birdie, eagle start and also finished in style with back-to-back gains.
Grace's unprecedented round featured five front-nine birdies and he was seven under for the day with two to play after draining lengthy putts for further gains at the 14th and 16th.
A wonderful second shot to the long 17th led to another birdie and meant Grace only needed to par the last to set a new benchmark. He did just that, two-putting from off the back of the green to earn a standing ovation from many in the grandstands either side of the 18th green.
World number one Dustin Johnson and defending champion Henrik Stenson were among others to go low on Saturday, carding 64 and 65 respectively to sit eight off the pace at three under alongside Rafael Cabrera Bello (67) and Chan Kim (67)
However, after a strong start to his round featuring three birdies in the first five holes, Rory McIlroy slipped out of contention - a double-bogey at 10 particularly damaging as the 2014 winner went round in 69. McIlroy is nine behind Spieth at two under and has far too much to do.