Jon Rahm became the world number one after a three-stroke victory at the Memorial Tournament on Sunday.
The 25-year-old became only the second Spaniard to reach the top ranking, joining Seve Ballesteros, after closing out his win at Muirfield Village.
Rahm carded a three-over 75 in the final round, producing a nervous finish after holding an eight-shot lead at one stage.
He made a bogey at the 10th and a double at 11 before dropping another shot at 14.
Rahm produced some magic at the par-three 16th to hole out from the rough, only to later be assessed a two-stroke penalty after it was ruled he moved his ball.
He finished at nine under after the penalty was handed down, three strokes clear of Ryan Palmer (74), to clinch his fourth PGA Tour victory.
The shot at 16 gave Rahm a boost and he told CBS: "It’s exactly what I needed.
"This golf course is no piece of cake in the best of conditions and with how firm everything was, any missed shot it was going to be brutally penalised and it happened, a couple of shots I barely missed like 14 and 15 and I ended up with a bogey and a par.
"But luckily, probably pulled out the best short-game shot I'll ever have, I hit a couple of good ones this week but that was unbelievable.
"I knew I could hit it close, I got a good lie and it was kind of into the wind but for that to go in was exactly what I needed."
Rahm was in control for the most part in Ohio, where dangerous weather led to a delay of almost an hour during the final round.
Matt Fitzpatrick (68) finished third, a shot behind Palmer, while Matt Wallace (72) and Jason Day (73) were tied for fourth.
Jordan Spieth (tied for 13th), Justin Thomas (T18), Rory McIlroy (T32) and Tiger Woods (T40) were further back.