Defending champion Tway, the 17-year-old son of PGA Tour winner Bob Tway, bested Chambersburg, Pa. native Clayton Rotz, 2 and 1. Vongvanij, meanwhile, squeaked past the youngest competitor in the field, 13-year-old David Flynn of Elk Grove Village, Ill., 2-up.
Tway jumped out to a 3-up lead and never looked back, improving his record at the event to 7-0. The 17-year-old Vongvanij built a 4-up advantage that he saw whittled down to a one-hole lead with three to play. He came up large on the 18th, however, drilling a five-wood to within five feet of the cup. He then two-putted to clinch the win.
In other first-round action, Rickie Fowler toppled John Peterson 4 and 3, while Philip Francis dismissed Peter Williamson 6 and 5.