At the age of 17, she was one of three co-leaders starting the final round of the 2005 U.S. Women's Open at Cherry Hills in suburban Denver. Pressel was tied for first on the 18th fairway when Birdie Kim holed out from the bunker just ahead to secure a one-stroke lead. Pressel then needed a birdie to tie, but made a bogey on the 18th to lose by two strokes. Her second-place finish gave her a share of the low amateur honors with Brittany Lang. Pressel played in a total of seven LPGA events in 2005 and made the cut in all of them, with a scoring average of 70.96 in 28 rounds.