INDIANAPOLIS, NOV. 30 -- Summer Sanders successfully defended her championship in the 200-meter individual medley and the unified German team made its debut in international competition with two victories tonight in U.S. Open swimming.

Christian Keller gave Germany a victory in the men's 200-meter medley and Mark Warnecke did the same in the 100-meter breaststroke.

Sanders, of Stanford, set a meet record of 2 minutes 15.01 seconds, finishing three seconds ahead of runner-up Lisa Summers in the opening event at the Indiana University Natatorium.

Keller, a former member of the West German team who placed second in the 200 medley in the recent German national championships, then won his race in 2:03.12, with Spain's Martin Zubero, representing Florida, placing second in 2:04.39.

"I was sick at the national championships and I was angry because I didn't qualify for the world championships," Keller said. "Tonight I went out and swam for myself. I want to be an Olympian and I hope this is a start."

Keller, one of four former West Germans among the 10 athletes representing their country, said he anticipated it would take some time for former East Germans to reach their previous high levels of performance.

"They're going through some drastic changes. They don't have the perks they used to have. They have to plan their time more, train less, go to class," he said. "Before, they could concentrate on swimming."

Stanford's Janet Evans, a triple gold medalist in the Seoul Olympics and the world record-holder in the women's 400-meter freestyle, won that event for the fourth time in five years, in 4:13.17. Jane Skillman, 17, of Princeton, N.J., was next in 4:15.04.

Warnecke won the 100-meter breaststroke in 1:03.80. Former Southern California star Dan Jorgensen won the men's 400-meter freestyle in 3:54.90, holding off the challenge of Olympic gold medalist Uwe Dassler, who set the world record of 3:46.95 while representing East Germany.