Tammy Smith, a 14-year-old gymnast from Allentown, Pa., captured three of the four top championships -- floor exercises, uneven bars and vaulting -- in the final round of yesterday's Capital Cup gymnastics competition at Montgomery College in Rockville.

Lisa Patti, a 12-year-old teammate from the Parkettes Gymnastics Club in Allentown, took first in the balance beam as the Parkettes dominated the meet, defeating their nearest rival, Omni Gymnastics of Northern New Jersey by a team score of 183.1 to 173.5.

Smith, who trained with MG Gymnastics in Silver Spring before switching to the Parkettes at the end of the summer, scored a 9.7 in the vault, a 9.5 on the bars, and a 9.5 in the floor exercise yesterday.

To the delight of a crowd of approximately 900, the 40 finalists -- 10 in each events -- swung, jumped, tumbled and danced in an impressive performance of acrobatics.

But from the minute that Smith, 4-feet-10 and weighing only 79 pounds, sailed through the air on her first vault, it was clear that she would be the gymnast to beat of the afternoon.

Smith, who will be 15 on Thursday, formerly lived in Westminster, Md., before moving to Allentown to join the Parkettes, considered to be the nation's best club gymnastics team after a victory earlier this fall over the National Academy of Gymnastics in Eugene, Ore.

Winner of the best all-around gymnast award based on the preliminary competition Saturday, Smith was closely followed by Mary Lou Retton, 13, of Fairmont, W.Va., and led by only 37.3 points going into the finals yesterday.

But Retton fell from the high bar in the uneven bar exercise and lost her balance and slipped from the balance beam while attempting a front flip in that exercise yesterday.

Nevertheless, she came back in the floor exercise to score a 9.6 -- high for the afternoon -- but not high enough to offset the advantage built up by Smith in floor competition Saturday when she took that event, 9.55 to Retton's 9.2.

"Mary Lou does a Russian theme for her floor routine," said her coach, Gary Rafaloski of Fairmont. "She combines great dancing with superior tumbling."

Lisa McVay of LaPlata, Md., a local favorite who competed internationally for the United States in Japan last summer, led in the balance beam exercise going into yesterday's rounds, but she twice fell from the beam for a score of 8.6.

McVay, who trains with Marvateens Gymnastics, host for the meet, fell while attempting a difficult back flip, a move she is attempting to perfect for use in international qualifying meets later this winter.