ZAGREB, YUGOSLAVIA, JULY 14 -- American runners and swimmers added six gold medals to their team total today at the 14th World University Games.

The Soviet Union leads the medal winners' list with 45 overall, 15 of them gold, while the United States has 36 medals, 13 gold. Romania also has 13 gold medals, 31 overall.

Lee McRae of Pittsburgh and Gwen Torrence of Decatur, Ga., took the men's and women's 100-meter dashes, respectively, and Patty Murray of Park Ridge, Ill., captured the women's 10,000 meters.

U.S. swimmers ended competition in their sport with three golds, including the women's 800-meter freestyle relay, in which they set a record.

The relay team of Mary O'Leary of Tucson, Ariz.; Lisa Meyers of Mission Viejo, Calif.; Cheryl Kriegsman of Los Angeles, and Mitzi Kremer of Titusville, Fla., swam 8:09.52, which easily bettered the previous Games record of 8:20.51 set in 1985 by the Soviet Union.

Alex Mlawsky of Sunnymead, Calif., and Tom Williams of St. Charles, Ill., won the longest and shortest men's swimming races.

Mlawsky finished first in the men's 1,500 meters freestyle in 15:23.22 after Williams captured the 50 meters, a first-time event at the Games, in 22.90.

McRae got off to an excellent start in winning the men's sprint by more than two meters in 10.07, fourth-fastest time in the world this year. Teammate Brian Cooper of Lake Charles, La., was second in 10.21, edging Bruno Marie Rose of France, the world indoor 200 record holder, who was timed in 10.25.

Torrence had only a fair start, but easily moved ahead in the last half of the women's race to win in 11.09. Irina Slusar of the Soviet Union was second.

Murray and China's Zhong Huandi waged a battle over 24 of the 25 laps in the 10,000 before Murray moved away in the final 200 meters to win in 33:11.27.

In other women's finals, Nawal El Moutawakel of Morocco, the only gold medalist in track and field from the 1984 Olympics competing here, won the 400-meter hurdles in 55.21. She is making a comeback after a leg operation.

Svetlana Isaeva of Bulgaria cleared 6 feet 4 3/4 inches to win the gold in the women's high jump, while Liliana Nastase of Romania took the women's decathlon with 6,364 points.

Italians took the final two women's swimming races. Manuela Dalla Valle won the 100-meter breaststroke in 1:10.54 and Ilaria Tocchini captured the 100-meter butterfly in 1:02.01.

In men's basketball, guard Troy Lewis of Purdue hit a three-pointer with 50 seconds to play to lead the United States to an 88-81 victory over Brazil.

Lewis, who had made two free throws in the final seconds Sunday to give the U.S. team an 83-82 victory over Spain, broke an 81-81 tie with the long jumper.