Van Pelt, who has six Top 10 finishes this season without a victory, did not suffer a bogey on a Congressional Country Club course that proved more difficult in the opening round than it did last year when it hosted the U.S. Open.
Seven sub-70 scores were shot Thursday and there were nine such rounds on the first day of the Open, including a 65 shot by eventual champion Rory McIlroy.
Tournament host Tiger Woods posted a 1-over 72 that left him in a tie for 30th place.
Van Pelt began his round on the back nine and made the turn in 1-under 34. He then holed out his wedge shot from 93 yards out at the par-4 first and birdied the second as well.