His once-comfortable lead gone, Rory McIlroy could have flinched.
Instead, he blew everyone away.
With a stunning display down the stretch, including a pair of eagles, McIlroy put a stranglehold on his third major championship by shooting a 4-under 68 Saturday, sending him to the final round of the British Open with a daunting six-shot edge.
McIlroy came into the day up by four after back-to-back 66s, only to start slowly and find himself tied for the top spot when Rickie Fowler birdied seven of the first 12 holes.
But, in a lightning-quick turnaround, McIlroy rolled in a 35-foot birdie at the 14th and an eagle at the 16th. Fowler bogeyed both holes, a five-shot swing in just under an hour.
When McIlroy made another eagle at the 18th after what he called "my two best shots of the day," he pushed his score to 16-under 200 and seized the largest 54-hole Open lead since Tiger Woods was six strokes ahead at St. Andrews in 2000.
No one has ever blown such a big advantage on the final day of golf's oldest major championship.
"I felt Rickie close to me," McIlroy said. " I was able to turn it on when I needed to."
That burst pushed him another step closer to the career Grand Slam at the tender age of 25. Boy Wonder already captured the 2011 U.S. Open and the 2012 PGA Championship, both in eight-shot runaways.
This is looking very much like another blowout.
"Obviously, it would be nice going to Augusta next year trying to complete" a Grand Slam, McIlroy said. "I've got a lot to play for tomorrow. It's a huge day for me."
Fowler settled for a 68 and a 206 total. Sergio Garcia shot 69 and was another shot back at 207.
"It's going to be difficult, but we'll give it a shot," Garcia said.
The R&A went with an unprecedented two-tee start and moved up the starting times, mindful of a forecast that called for a chance of severe thunderstorms. The bad weather didn't materialize while the golfers were on the course.
There were a few brief showers, but this links along the Irish Sea was no match for the world's best players - the greens softened by the smattering of rain, nary a stiff breeze to put some bite into Royal Liverpool.
"I think everyone was getting ready for a hurricane," said Keegan Bradley, whose 69 made him one of 17 players to break 70. "But it's as nice as we could imagine."
Fowler's bogey at the 14th dropped him two shots back, but it was the par-5 16th - one of the easiest holes on the course - that really sent him tumbling.
He drove it into a bunker, was fortunate just to get out, and missed a par-saving putt from 8 feet. That looked especially bad when McIlroy came along a few minutes later in the final group, hit a soaring second shot that curled toward the flag, then rolled in a 35-footer for eagle.
The leader pumped his fist, sensing that he had regained control of the tournament.
Fowler birdied the final hole, but lost another stroke when McIlroy crushed a drive of nearly 320 yards down the middle of the fairway, and followed with a 5-iron from 237 that pulled up about 10 feet from the cup.
"As soon it left the club, I knew it was all over it," McIlroy said. "Obviously, that's a nice way to finish. It gives me a good cushion going into tomorrow."
Dustin Johnson (71) joined Garcia at 207. France's Victor Dubuisson shot 68 and was at 208. Italy's Edoardo Molinari (68) was another stroke back, while the group at 210 included world No. 1 Adam Scott (69), 21-year-old Italian Matteo Manassero (68), and major winners Jim Furyk (71) and Charl Schwartzel (72).
Darren Clarke matched Jordan Spieth for the best round of the day with a 67 that included an amazing stretch of six birdies in seven holes. It was better score than any of Clarke's rounds when he won the Open at Royal St. George's in 2011.
David Hearn of Brantford, Ont., had a pair of birdies and a bogey for a round of 71 which left him at 2-under for the tournament.
McIlroy built his 36-hole lead with two straight 6-under 66s. He got off to a shaky start Saturday, squandered a booming drive in the middle of the fairway, his next shot catching a deep pot bunker next to the green. He barely got it out of the sand and took bogey.
Johnson, playing in the final group with the leader and his closest challenger at the start of play, stuck an approach to about 5 feet and rolled in the birdie.
Just like that, McIlroy's lead was cut in half.
But Johnson faded.
So did everyone else.
Defending champion Phil Mickelson was hoping to make a big push after shooting 70 on Friday. But Lefty made three bogeys on the front side and, even with a rally after the turn, still managed just a 71 that left him too far back.
He knew he should have done better.
"It's as easy as I have seen the course play," he said.
Coming off one of the worst Open rounds of his pro career, Tiger Woods teed off in the final group at No. 10, still clinging to the hope of mounting a Paul Lawrie-like comeback.
No chance, even after birdies at his first two holes. Woods made a double bogey at the second - his 11th hole of the day - and a triple bogey at the seventh for a 73 that left him a staggering 19 shots behind McIlroy.