Dan Magnus of Rockville waged a magnificent karate fight last night at the Sheraton Washington Hotel. But his opponent, Oliver Miller of Starkville, Miss., was even better.

Magnus (31-9), ranked fifth in the world, was fighting his second bout in 20 months, after open heart surgery delayed his career. And he went the full 10 rounds with Miller (25-4), the second-ranked full-contact karate fighter in the world.

"I thought I had it," said Magnus, 28, who lost a unanimous decision by the scores of 94-96, 94-97 and 93-97. "He was tougher to push back than I thought. I let him flurry too much. I was hitting him with harder punches."

Miller's hands were much too fast and too accurate for Magnus. Miller took Magnus to the ropes a number of times and scored heavily with right and left combinations to the body. Magnus, whose strength is in his feet, could not shake Miller with a variety of front, side and spinning back kicks.

The crowd of more than 1,500 was entertained by a seven-bout card of boxing and full-contact karate, the first of a nine-card series called the Night of Champions.

In the co-feature event, Manning Galloway (43-7-1, 20 knockouts) of Columbus, Ohio, won a unanimous decision over Lloyd Taylor (21-4, 16 knockouts) in a 10-round welterweight boxing match.

In the opening fight, Greg Maye of Hyattsville won his third fight without a loss and ruined the professional debut of Clifford McPherson of Baltimore with a unanimous decision in three rounds of light middleweight full-contact karate.

Keith Corbett (4-2, four knockouts) of Cherry Hill, N.J., earned a third-round technical knockout over Baltimore's William Reed (2-3, 1 knockout) after Reed's manager, Albert Howard, did not allow his fighter to continue because Howard said Reed had been suffering stomach cramps since the first of a scheduled six-round junior lightweight boxing match.

Jerry Williams (8-2) of Philadelphia won a unanimous decision after an eight-round battle with Anthony Crudup (15-6, eight knockouts) of Fort Washington.

In another karate match, Chuck Bittle (11-4) of Washington earned a unanimous decision over Richard Huggins (10-6) of Glen Burnie, in a five-round lightweight contest.

Welterweight Kervin Carter (1-4) of Washington came back after losing the first round and decisioned Ernest Pee (1-1) of Washington in a four-round boxing bout.