American Scottie Scheffler carded a closing two-over-par 74 at Muirfield Village to finish on eight-under-par and secure a confidence-boosting victory ahead of next week's US Open at Pinehurst, North Carolina.

Scheffler led by four shots after Saturday's third round, but saw that lead gradually evaporate as Morikawa chased him down in perfect conditions on the challenging 7,569-yard, par-72 course.

Despite an error-filled round that included three bogeys and just one birdie, Scheffler's unflappable temperament proved decisive in keeping the New Jersey native at the top of the world rankings.

"Amazing," said Scheffler after his victory in Ohio. "I feel like I've had some close calls in this tournament. This is a tough place to finish, as you saw today."

Scheffler was congratulated by tournament host and golf icon Jack Nicklaus as he walked off the 18th green after a victory that earned him $4 million.

"I remember shaking Mr Nicklaus' hand a couple of years ago and he told me that I didn't make the putt that day, but that one day I would make the putt and be able to shake his hand. So to shake his hand today was surreal," said the Memorial Tournament winner.

Californian Collin Morikawa finished one shot behind on -7, while Canadian Adam Hadwin was third on -4 after a final round of 74.

South Africa's Christiaan Bezuidenhout finished fourth on three under par after a final round of 72, while England's Matt Fitzpatrick, Sweden's Ludvig Aberg and Austria's Sepp Straka were all tied for fifth on two under par.

Scheffler's victory comes against the backdrop of his arrest for driving during last month's PGA Championship, an incident that will haunt him for the rest of his career.

The 27-year-old golfer was taken to jail, spent hours behind bars and had his mug shot taken. Scheffler was arrested before dawn at the entrance to Valhalla on four charges stemming from his attempt to drive around a police roadblock investigating a fatal car accident.

Although all charges against Scheffler were dropped on 29 May, the world number one said that despite the charges being dropped, the arrest still lingered, although winning the tournament might help him forget about it.

"It's not something I like to relive, simply because it was quite traumatic for me to be arrested when I was on the golf course. It's not something I like to talk about and it's something I hope to put behind me, but if the charges are dropped, that's just the beginning of putting it behind me," said the world number one.

"It was definitely a bit of a relief, but not a total relief because it's something that will always stay with me somehow. That mug shot, I'm sure, is not going anywhere anytime soon.

"Part of the recovery process from the whole scenario is your brain trying to figure out how this happened, and I will probably never figure out why or how this happened.

"It's just one of those things. It will always be ingrained in my season this year, but in time people will forget about it".

His season has been a memorable one, with victories at Bay Hill, The Players, the Masters and Heritage, as well as runner-up finishes at Houston and Colonial.