The American Capitals advanced to the championship game of the Urban Coalition Summer Basketball League last night with a 146-140 victory over the Big M Trotters at Dunbar High School. The game ended with 34 seconds left after referee Bob Golsby ejected Big M Trotters Coach Melvin Roberts.

Roberts was on the court, complaining about the officiating, when the altercation started. Both Golsby and Roberts had to be restrained and, after several efforts to restore calm, the game was called.

In the other semifinal, Tyrone Woods' five straight foul shots broke a 138-138 tie in leading the Baltimore Lakers to a 165-149 victory over Duren Enterprises. The final will be today at 4 p.m.

The American Capitals trailed, 90-79, with 7:46 left in the third quarter. The Capitals, who may be joined today by the Washington Bullets' second-round draft choice, 7-foot-6 Manute Bol, cut the lead to 92-85 with 6:14 left and trailed, 107-103, at the end of the period.

A jumper by former DeMatha guard Bob Ferry Jr. cut the lead to 107-105 and Tracy Jackson, former Paint Branch High School and Notre Dame forward, tied it at 107 with 10:50 left.

In the first game, the Lakers' Joe Pace, a former Bullets reserve, tied it at 138 with 4:28 to play after Johnny Jones, a former UDC player, gave Duren Enterprises the lead. Enterprises missed a chance to go ahead when Bernard Campbell was called for charging.

The Golden State Warriors' Eric Floyd, formerly of Georgetown, played for Duren Enterprises and led the way with 46 points. Former Maryland guard Ernest Graham led Baltimore with 44. John Duren had 27 for the losers.