PORTRUSH, United Kingdom (AFP) — Scottie Scheffler closed in on a maiden British Open title on Saturday, opening up a four-shot lead ahead of the final round at Royal Portrush with another imperious display.

The world No. 1 was unflappable despite some Rory McIlroy fireworks in front of him, easing to a bogey-free, four-under par third round of 67 to reach 14-under for the tournament.

Scheffler, who is targeting a fourth major title and the third leg of a possible career Grand Slam, strengthened his grip on the Claret Jug by stretching his one-stroke overnight advantage.

The American has continued his brilliant recent form in Northern Ireland after arriving this week on a run of 10 successive top-10 finishes, including three wins.

He is now on the brink of becoming the first world No. 1 to win the British Open since Tiger Woods clinched his third title in 2006.

"I'm just trying to execute, not overthinking things," said Scheffler, who has won his last nine tournaments when holding the 54-hole lead.

"I feel like I've been doing the right thing so far, and I'm looking forward to the challenge of tomorrow."

China's Li Haotong battled hard to stay in touch, finishing the day alone in second place on 10-under overall after a 69.

Matthew Fitzpatrick sits third, five shots behind Scheffler, as his challenge faltered during an up-and-down 71.

Home favorite McIlroy delighted the crowd with a five-under 66 to reach minus eight but will need some unlikely help from Scheffler on Sunday to win a second British Open after his triumph in 2014.

Fitzpatrick drew level with Scheffler early in the round by chipping in for an eagle on the par-five second, as the leader three-putted for par.

But Scheffler, the PGA champion, cruised back in front with an eagle on the seventh hole, backed up by a birdie on the eighth.

He stayed bogey-free courtesy of a gusty par save after finding thick rough to the left of the 11th green, before getting up and down again on 14.

The 29-year-old dealt another blow to the chasing pack with a birdie on the difficult 16th, dubbed "calamity corner," before closing out his round with two solid pars.

Li, hoping to become the first Chinese man to win a major title, hung in to reach the turn at nine-under overall, four shots adrift.

He emerged as Scheffler's closest challenger while others slipped back, making three birdies on the second nine before a closing bogey.

Fitzpatrick was only two behind Scheffler at the halfway point of the third round as he tried to boost his bid to become the first English winner since Nick Faldo in 1992.

But three bogeys on the way in left him with a mountain to climb.