Updated

Matthew Fitzpatrick never looked overwhelmed in his U.S. Open debut alongside defending champion Justin Rose and Phil Mickelson.

The U.S. Amateur champion opened with a 1-over 71 on Thursday in his final event before turning pro. He had four birdies, five bogeys and a one-shot penalty in a performance that left him "pleased and disappointed at the same time, really."

Fitzpatrick, with boyish looks younger than his 19 years, played alongside Rose and Mickelson in one of the day's most watched groups at Pinehurst No. 2.

The Englishman birdied two of his first three holes and avoided major trouble, leaving him solidly in the upper half of the leaderboard.