Spaniard Jon Rahm, 21, impressed in his first professional start at the Quicken Loans National, shooting a seven-under par 64 at Congressional Country Club in Bethesda, Md., to take a one-stroke lead.
"I was just hot off the tee," said Rahm, the only amateur to make the cut at the U.S. Open last week. "I wasn't cruising. It was obviously a good day. I was really comfortable off the tee with the driver, hitting it good, hitting it straight, so that allowed me to be a little more aggressive."
Jhonnatan Vegas is in second with a 65, while Ernie Els, Bill Haas and Harold Varner III are all tied for third at five under, two strokes behind Rahm.
Smylie Kaufman is one of 10 players in a tie for 10th following a first round four-under 67. He is three strokes back.
Rickie Fowler and Patrick Reed each shot three-under 68.
Jim Furyk had a mediocre first round following a T2 at last week's U.S. Open, shooting a two-over 73. He is nine strokes off the lead.
[Click here for the entire leader board from Congressional.] (http://www.golfdigest.com/story/pga-tour-leaderboard)