Jon Rahm is the new world No. 1 male player after he dominated the Memorial Tournament on the final day at Muirfield Village.

Australia’s Jason Day finished tied-fourth behind Rahm, scrambling a last-round 73 to log his equal-best finish of the season.

At just 25, Rahm is the 24th world No. 1 since the rankings began, and the third-youngest ever. He is the second Spaniard to hold the mantle behind the late, great Seve Ballesteros, whose feats inspired him.

Rahm was the world No. 1 amateur six years ago when he was at Arizona State University, but he has transformed into a brilliant professional player, and he was at his best in tough conditions on the final day.

It was not a day without drama, and Rahm had to get through a rules issue to reach the finish line. Eight shots ahead through eight holes and seemingly home and hosed, the Spaniard went through a wobbly stretch including a double bogey seven at the par-five 11th hole.

Reaching the 16th tee, his playing partner Ryan Palmer had closed within three.

Rahm missed the green at the tough par-three left, short-siding himself, but promptly hit what he called “the best short-game shot of my life”, an exquisite flop shot with a full swing that landed on the edge of the green and ran straight in the cup for birdie. It was a shot out of the Ballesteros playbook.

That appeared to be the winner, right there. But television replays showed that Rahm had accidentally moved his ball a few millimetres by placing his lob wedge in the long grass in preparing to take the shot. Although he was never told about the problem on the course, he was later penalised two shots by the tour.

“I did not see or feel anything,” he said later. “Had I seen it, I would have said so. I just never did.”

Fortunately for everyone, the incident did not change the result although instead of a birdie, Rahm was assessed as having made bogey at the 16th.

Even with the penalty, Rahm shot a final-round 75 and at nine-under par, won by three shots from Palmer. Confirming 2020 as the weirdest year for professional sports, he walked down the 72nd hole with scarcely a cheer audible in the crowdless arena in Ohio, then bumped fists with Jack Nicklaus, who runs the tournament.

Rahm replaces Rory McIlroy as world No. 1.

He said he would process the news over time, noting family members who were unable to join him because of quarantines in place. “I’m just happy for my family, happy I could do it for my Mum and my Grandma and the rest of the family.”

Day completed his fifth tournament in as many weeks with a sore back but two consecutive top-10 finishes to show some improvement in his form. His putter was cold today, but he fought doggedly to post a score that was well under the day’s average on brutally firm greens.

He is not playing in Minnesota next week.Memorial Tournament leaderboard