Molinari recorded his fifth European Tour win and first Rolex Series titles in May 2018, with victory in the European Tour's flagship event, the BMW PGA Championship. He produced a flawless final round to see off Rory McIlroy by two strokes. The win took Molinari level with Costantino Rocca, for most European Tour wins by an Italian. In the same year, Molinari won the Quicken Loans National in a dominating fashion by shooting a 62 on Sunday to win by eight strokes, the first PGA Tour win for an Italian since 1947.