Donald's sole win on the PGA Tour was the 1989 Anheuser-Busch Golf Classic. He lost on the first playoff hole in sudden-death to Hale Irwin at the 1990 U.S. Open in Medinah, Illinois, after they had both finished the 18-hole playoff in 74. Donald missed a 15-foot par putt on the 18th hole of the Monday playoff which would have given him victory.
In the 1990 Masters Tournament Donald tied the record for the lowest opening round score in the history of the tournament, shooting an 8-under-par 64 to equal the lowest first round at Augusta by Lloyd Mangrum in 1940.[2] Donald described his 64 at Augusta as "the round of my life" but followed it up with a second round of 82.[3] He finished the tournament in 47th place.