Nancy Isaak, 15, a freshman at Kailua High in Honolulu and a tennis player for just four years, defeated Joyce Yee, the first-ranked Hawaiian woman, in the semifinals, and then outlasted Judy Leong 4-6, 6-3, 7-5 to win the Hawaii women's singles title.

Doug Stephens, 14, an Esparto, Calif. athlete who switched from running to high jumping five years ago when he lost his left leg in an accident, leaped 5 feet 4 inches for victory in the Yolo County, Calif. track meet. He has cleared 5 feet 7½ inches in practice.

Barbara Thomas, 32, a Dallas housewife who has been skeet shooting for 15 months, won the .410-, 28-and 20-gauge events in the Dallas Gun Club's Metropolitan 300 Open tournament, and edged Defending Champion Evelyn Jones for the overall title with 276.

Brian Edgerly, 20, a 6-foot, 185-pound junior majoring in philosophy and religion at Colgate University, led the baseball team with a .396 BA and was voted captain for next year. The popular athlete had already been elected soccer co-captain and hockey captain.

Janet Welch, 16, of Alexandria, Va., who plays water polo for the Northern Virginia Aquatic Club in Arlington, led her team in assists as it won the national senior women's indoor title in four straight, and was named the tournament's most valuable player.

Steve Opperman, 22, who has been playing golf since he was 8 in his native San Francisco, won the Western Amateur in Tucson with a 3-and-2 victory over the favorite, Dr. Edgar Updegraff, a Walker Cup player and two-time Western champion.