On June 3, 2018, DeChambeau won the Memorial Tournament in Dublin, Ohio, in a sudden-death playoff against Kyle Stanley and An Byeong-hun, after the three finished regulation play tied at −15. After Stanley bogeyed the first hole of sudden death, DeChambeau then proceeded to win with a birdie on the second hole, giving him his second win on the tour.
Fowler's first PGA Tour event as a professional was the Justin Timberlake Shriners Hospitals for Children Open where he finished tied for seventh. His second PGA Tour event was at the Frys.com Open played at Grayhawk Golf Club in Scottsdale, Arizona. He finished tied for second after losing to Troy Matteson in a three-way playoff that included Jamie Lovemark. Fowler's score of 18-under-par included a hole-in-one on the fifth hole in his final round. Fowler also notched an eagle in each of his four rounds.
BMW Championship: At No. 22 in the FedExCup standings heading into the third Playoffs event, the BMW Championship, he bogeyed No. 17 in a final-round even-par 72 to miss advancing to the TOUR Championship by half a point, finishing the season No. 31 in the FedExCup standings. Charl Schwartzel fired a final-round 8-under 64 to claim the No. 30 position.
Lowry elected to turn professional the week after his Irish Open triumph, meaning that he would miss out on the opportunity to play in the Walker Cup in September 2009. He made his professional début on 28 May at the European Open, where he shot 78 in the first round to end the opening day almost at the back of the field, and went on to miss the cut following a second round 73.