Ice-cool Scheffler holds on to clinch PGA Tour Memorial crown
Scheffler fired a closing two-over-par 74 at Muirfield Village to finish on eight under, sealing a morale-boosting win as he prepares for an assault on next week's US Open at Pinehurst in North Carolina.
The American had led by four shots after Saturday's third round, but saw that lead steadily evaporate with playing partner Morikawa in pursuit in perfect conditions at the demanding 7,569-yard par-72 layout.
But despite an error-strewn round that included three bogeys and only one birdie, Scheffler's unflappable temperament proved decisive.
"Pretty amazing," Scheffler said after his win. "I feel like I've had some close calls in this tournament. This is a tough place to close it out as you saw today. The golf course was playing so tough."
Scheffler was congratulated by tournament host and golf icon Jack Nicklaus as he left the 18th green following a win which earned him a cool $4 million (£3.14m).
"I remember shaking Mr Nicklaus's hand a few years ago and he told me I didn't make the putt today, but one day I'll make the putt and be able to shake his hand. So to be able to shake his hand today was pretty surreal."
Morikawa, who shot a closing 71, had moved to within three early in the round after grabbing his first birdie of the day on the second hole.
Scheffler however extended his advantage to five shots on the sixth when he rolled in a nine-foot put for birdie as Morikawa bogeyed.
Costly miss
But Morikawa bounced back immediately on the seventh with a birdie and then grabbed another after rolling in an eight-foot birdie putt on the ninth to reach the turn at one under for the day.
That left him two off the lead after Scheffler's bogey on the eighth, and Morikawa kept up the pressure with a monster 32-foot birdie putt on the par-three 12th to move within one of the lead.
However Morikawa missed a golden chance to grab a share of the lead on the par-five 15th, misreading the line to roll a six-foot putt just wide leaving Scheffler on pole heading to the final three holes.
That miss proved costly for Morikawa on the par-three 16th, where after landing off the green with his tee shot he was left with a 22-foot putt to save par after chipping on.
He missed the putt and then could only watch as Scheffler coolly drained a 15-footer for par which left him two shots clear with two to play.
There was a glimmer of hope for Morikawa on the 17th, when Scheffler bogeyed after missing a 10-footer to save par.
But once again Scheffler's knack of regrouping under pressure came to the fore on the par-four 18th. After hitting his second through the back of the green he chipped on and then sank a five-footer for victory.
Morikawa finished one back on seven under, while Canada's Adam Hadwin was alone in third on four under after a closing 74.
South Africa's Christiaan Bezuidenhout was fourth on three under after a final round 72, with England's Matt Fitzpatrick, Sweden's Ludvic Aberg and Austria's Sepp Straka tied for fifth on two under.
