A spectacular second-half display of ball control and shooting by guards Michael Adams and John Bagley brought Boston College an 82-75 Midwest Regional upset of No. 2 De Paul today. It was the third straight year that the Blue Demons have been eliminated in their opening NCAA tournament game.

"It's a bitter pill to swallow," said De Paul Coach Ray Meyer. "We were outplayed and deserved to lose."

Bagley scored 26 points and Adams 21 to lead the Eagles (21-9), who will meet Kansas State in St. Louis Friday in the regional semifinals. The Wildcats beat Arkansas, 65-64, earlier in the day as Scott Hastings of the Razorbacks missed the potential game-winner with one second left.

De Paul was quickly knocked out of the 1980 tournament by UCLA, 77-71, and last year by St. Joseph's, 49-48. Both times, the Demons had finished the regular season No. 1.

On the eve of today's game, Meyer had said his team had two strikes against it, and promised that if his team was defeated it would be beaten while playing its best.

De Paul (26-2) came out playing its best, moving to an 8-0 lead and not allowing the Eagles a point for the first 3:24. But Boston College used a full-court press to rally within a point, 34-33, at halftime.

The press was an unexpected problem, said Meyer. "I certainly didn't think it would (be a problem) going into the game," he said. "It really bothered us."

Adams and Bagley came up with steals, frequently saved the ball when it was heading out of bounds and consistently made either long-range jumpers or driving layups.

The pressing Eagles scored 10 straight points midway through the second half, including three baskets by Bagley, to take command. Adams, averaging 3.9 points per game, had 13 points.

The Eagles went ahead, 70-59, and then withstood a De Paul rally with accuracy from the free-throw line. Bagley and Adams each made four free throws in the final two minutes to hold off the Blue Demons.

De Paul lost five players via fouls and was called for 35 violations. Tyrone Corbin and Skip Dillard of De Paul fouled out, and Blue Demon all-America Terry Cummings played the final 13 minutes with four fouls. Cummings finished with 20 points.

"The officiating didn't beat us," said Meyer. "That's part of basketball."

Boston College Coach Tom Davis, who saw his team fall behind early, admitted, "I was afraid we were going to get blown out . . . We were playing hard but we were trying too hard. We just had to get settled down. We beat a great team and just an unbelievable person in Coach Meyer."

In the Kansas State-Arkansas game, the Wildcats built a 10-point lead in the second half on the shooting and floor play of Tyrone Adams then hung on to win by one. Adams finished with a game-high 21 points.

Kansas State is 23-6. Arkansas, still the winningest team in college basketball over the last six seasons, finished its year with a similar record.