PAN AMERICAN GAMES : A Win Some, Lose Some Day for U.S. Athletes

MAR DEL PLATA, Argentina — The United States vs. the hemisphere was a gold-medal split at the swimming and diving pools Sunday, and success in gymnastics, cycling and roller skating made up for baseball and soccer losses at the Pan American Games.

The St. John’s baseball team, representing the United States, lost its second game in a row. As Argentina did the previous day, Mexico jumped to an early lead and beat the Americans, 7-2.

Mexico also did well in diving as Fernando Platas upset Americans Mark Bradshaw and Kent Ferguson on the three-meter springboard. Bradshaw got the silver medal, while Ferguson finished fourth.

The U.S. women’s gymnastics team, led by Olympic medalist Shannon Miller of Edmond, Okla., shattered the games record with 388.375 points to take the gold.

A Brazilian and a Canadian won gold medals in swimming to go with victories by Angel Martino of Americus, Ga., in the 100 freestyle; Seth van Neerden of Wilmington, Del., in the 100 breaststroke; and by the U.S. team in the women’s 800 freestyle relay.

Martino, 27, married and still not sure whether she wants to swim in the 1996 Olympics or start a family, set a Pan-Am record of 55.62 seconds in the 100.

The U.S. 800-meter relay team of Dady Vincent, Trina Jackson, Catherine Fox and Cristina Teuscher won in 8:07.30, shattering the U.S. team’s Pan-Am record by 4.17 seconds.

Cyclists Clay Moseley of Albuquerque, N.M., and Dede Demet of Colorado Springs, Colo., won gold medals in the individual time trials.

The American women’s volleyball team fared better than the baseball players against the hosts, routing Argentina in three games.

The U.S. soccer squad was, in turn, beaten, 3-0, by heavily favored Argentina Sunday night.