All but three seeded players have advanced to the round of 16 in the men's division of the USTA National Amateur Indoor Tennis Championships at Crystal City Racquet Club. However, second-seeded Norm Schellenger had to win a second-set tie breaker yesterday after losing the first set. He finally beat South Africa's Russell Mathey, 1-6, 7-6, 6-2.

Schellenger broke serve only three times, but when he went ahead, 4-2, on a service break in the final set the match was over. "That was close," Schellenger said. "I was returning serve poorly. My whole game revolves around return of serve. I wasn't confident until after I won the tie breaker. On his match point, I came to the net so he would have to hit a winner to win it."

Fourth-seeded Paul Annacone, the NCAA's sixth-ranked player, survived a ragged second set to beat West Virginia's Pete Perrotta, 6-0, 3-6, 6-4. Annacone, 19, a sophomore, plays No. 1 for Tennessee.

Fifth-seeded Phil Tuckniss of Zimbabwe, his nation's fourth-ranked amateur, beat Kirk Baylor of Reston, 6-0, 6-0. Tuckniss has lost only one game in four sets. Seventh-seeded Ahmed El Mehelmy of Egypt, South Alabama's top player, outlasted the Naval Academy's best, Bayley Taff, 6-0, 4-6, 6-3.

Brown University's Andy New, a graduate of Churchill High School, lost to 10th-seeded Fred Perrin of South Florida, 6-7, 6-3, 6-2.

Seventh-seeded Amy Kneale, the former Wakefield High School star, defeated Centennial High School's Diane Jamison, 4-6, 6-1, 6-2. Kneale, a sophomore at South Carolina, is Virginia's top-ranked amateur.

"My concentration wasn't that great at first," said Kneale, who is still suffering from bronchitis. Princeton's Jan Shelburne, a Walt Whitman High graduate, routed Pam Perrotta 6-0, 6-1.