Howard Univesrity and Navy, each playing its best basketball of the season and seeking a postseason bid, are in must-win situations Saturday.

Howard (19-7), which received a first-round bye, will play North Carolina Central (8-17) in one Mid-Eastern Athletic Conference semifinal game Saturday night at 8. South Carolina State (11-6) will meet Florida A&M in the tournament semifinal at 6.

The championship game will be Sunday at 4.

In tonight's first-round games, N.C. Central edged North Carolina A&T, 80-79, in overtime and South Carolina State defeated Morgan State 71-59, and Florida AM ripped Delaware St., 69-67.

Should Howard win the tournament, a National Invitation Tournament bid is possible.

Surprising Navy (14-12) topped St. Francis, Pa., 75-62, in an ECAC-South semifinal game Thursday night and will go against rugged Old Dominion (24-4) for that tourney's title and an automatic berth to the NCAA. The game will be played at the Hampton (Va.) Coliseum at 1 p.m. Saturday.

The last time Navy appeared in the NCAA tournament was in 1960. The Mids who have depended on their clawing, man-to-man defense, will have problems with Old Dominion. The Monarchs, led by 6-foot-6 forward Ron Vanentine, destroyed Navy, 58-44, last month. Win or lose against Navy, Old Dominion is expected to receive a bid to the 48-team field NCAA.

An NIT bid for Howard would be the climax to what already has been a successful season, according to Bison Coach A. B. Williamson.

"Our season goal was to win 20 games and the MEAC tournament," said Williamson. "We can achieve both goals this weekend. That is the most important thing for us right now. Of course, we'd love to have an NIT bid, and with a 21-7 record and the schedule we played, I feel we should be considered."

The Bison, who reached the final of the MEAC tournament twice in the last four years under Williamson, will call on their all-MEAC forward, 6-8 James Ratiff, and 6-7 Larry Spriggs to lead them Saturday.

Ratiff, Howard's leading scorer the last nine outings, is averaging 20.5 points and 9.3 rebounds, both team highs. Spriggs is averaging 13.9 points and 6.8 rebounds and usually guards the opponent's best inside player.

Howard has won six straight and eight of its nine conference games.

"In past years, I've had apprehension before the tournament," said Williamson. "This year, I have none whatsoever. The only way we can lose is to make mental mistakes.

"Right now, we're playing as well as we have all year. Ratiff and Spriggs will play their usual games. (James) Terry, our 6-10 center, and point guard rodney Wright will also have to play well if we're going to have good games."