American University, which had a five-point halftime lead, increased it to 13 points midway through the second half and upset host South Alabama, 70-66, in the championship of the Senior Bowl basketball tournament tonight at Municipal Auditorium.

Ed Sloane scored 22 points to lead American (5-4) and Mark Nickens had 16--but the Eagles' playmaker, 5-foot-11 junior Gordon Austin, was named the tournament's most valuable player.

Austin scored 12 points in the title game, including American's last six points, all on free throws. Austin made all 18 of his free throw attempts in the tournament and had a career-high 12 assists tonight. He scored 10 points in the Eagles' first-round victory over North Carolina-Wilmington.

"He's a classic point guard," Coach Gary Williams said. "He's a throwback to the 1960s."

American rode the scoring of Sloane and Nickens to a 38-33 halftime lead. Then the Eagles outscored the taller Jaguars, 12-3, in the first 9:37 of the second half for a 52-39 lead.

American went to a four-corner delay game with five minutes remaining and a 62-49 lead.

The strategy was effective, and South Alabama was forced to foul, sending the Eagles to the free throw line seven times in the last four minutes.

"This is a tremendous win for this school," said an emotionally spent Williams, who called the victory an upset. "Anytime you win a tournament on someone else's court it has to be an upset," he said.

South Alabama had won five of the last six Senior Bowl tournaments.

Williams said his game plan was to use American's superior speed to offset South Alabama's height advantage.

"We had to get the ball inside," Williams said. "We couldn't be intimidated if they blocked some shots. We wanted to play aggressively and show them we were not intimidated."

Reggie Hannah led South Alabama with 18 points and Damon Bryant had 12. South Alabama's late rally was hampered by the fact that Coach Cliff Ellis used his last timeout with 5:42 remaining.

"That's the worst situation you can be in as a coach," Williams said. "One minute left and up by six or eight points. But Austin made some big free throws for us."

Joining Austin on the all-tournament team were Nickens and Sloane, Hannah and Bryant, and Shawn Williams of North Carolina-Wilmington, who scored 38 points in his team's 80-52 victory over Grambling for third place.