Brigham Young's Danny Ainge, who woke up this morning with back spasms and didn't know if he'd be able to play, scored 37 points in sepcutacular fashion to hand UCLA its worst NCAA tournament defeat, 78-55, this afternoon.

UCLA hasn't been eliminated in its opening tournament appearance since 1963, when the Bruins lost to Arizona State by 14 points.

In the second game of the East Regional doubleheader, Notre Dame guard Tracy Jackson scored 21 points and had 12 rebounds and the Irish were able to hold off stubborn James Madison, 54-45. The downfall of Madison was its 35 percent second-half shooting after it had converted 63 percent in the first half.

For 30 minutes, the Dukes of Harrisonburg, Va., hung close before Jackson scored nine points in the final 10 minutes to send the Irish on the road to Atlantia for a Thursday night East Regional semifinal against BYU.

It was a slow-down road for the Irish, but it was a superspeed highway for BYU and Ainge, who will resume his professional baseball career as a third basemen with the Toronto Blue Jays as soon as the Cougar season ends. The way the Western Athletic Conference's third-place team played today, that might not be until March 30, when the NCAA final is contested in Philadelphia.

Aigne tied today's game at 21 on an 18-footer with three minutes left in the first half. Seconds later, Steve Craig's steal and basket put the Cougars ahead, 23-21, and BYU (24-6) never trailed.

The Cougars took a 31-22 halftime lead on nine-for-11 shooting and 23 points by Ainge. They beat the mercurial Bruins (20-7) in a running game.

In what may have been Larry Brown's last game as UCLA coach, the Bruins played much of the time without their best shooter and quickest player, Rod Foster, who sprained an ankle. The other Bruin guards did little, if any, penetrating against BYU's tight 2-3 zone and seemed content to take outside jump shots; their impatience was a big factor in 34 percent field goal accuracy.

BYU is much bigger (three inches per man taller across the front line), and presumably slower than UCLA. But the Cougars scored continuously of the transition game, outscoring UCLA, 7-0 and 14-2, to start the second half.

"Nobody's run against us like they did today," said Foster, who made only one of five shots in 14 minutes. "We also had trouble with their size inside. Nobody was blocking out. We started to press when they got the big lead.

"BYU's a fine ball club, but we didn't play hard enough. I'd hate to say we were looking ahead to Notre Dame and Virginia (also in this regional), but . . ."

The Bruins didn't seem to have a clue as how to stop the Cougar front line rebounding of 6-8 Fred Roberts, 6-10 Steve Trumbo and 6-11 Greg Kite. The Bruins, who average 6-6 across the front line, were outrebounded, 43-36. Kite, Roberts and Trumbo had 31.

But the Bruins' biggest problem was Ainge, the 6-5 senior guard who may be the most prolific outside scorer in college basketball. He scored 11 straight points for the Cougars early, and the last eight in the first half. In all, he made 14 of 22 shots from the field, including a flashy, spinning scooper off glass that put BYU ahead, 64-46, with 4:30 left to play.

"As good as Ainge is, the other BYU players making the sacrifice was the difference," said Brown, who refused to discuss reports that he is about to become coach of the New Jersey Nets. "It's beautiful the way they surround the star and help him do his thing."

BYU Coach Frank Arnold said Ainge scored 31 points in a game earlier this season after he got sick from a pregame breakfast and threw up throughout the game.

"We gotta do something to keep this kid sick or injured," he said.

Ainge said he was in pain this morning, but took heat treatments for the back spasms that have mysteriously bothered him all week, and felt a little better by game time.

Actually, it was UCLA's excellence on defense early in the game that forced Ainge to shoot more.

"UCLA's zone pushed our offense out farther than we'd like," said Arnold.

"We got out of our comfort zone. We got too fast and did more freelancing than I'd like to see in our offense." Ainge began to shoot from up to 25 feet.

UCLA front court men Darren Daye and Mike Sanders scored most of their 12 and 14 points, respectively, in the second half when BYU was comfortably ahead.

In the second game, James Madison (21-9) just couldn't stop Jackson, a senior from Silver Spring, Md. Notre Dame center-forward Orlando Woolridge was ineffective with a thigh bruise (two rebounds, five points), so Irish Coach Digger Phelps told Jackson to take up the slack and concentrate on rebounding.

Not only did Jackson rebound, but his points in the final 10 minutes made the difference, including the tip-in of a teammate's missed shot when the Dukes had pulled within 38-35 with less than nine minutes remaining.

Jackson's rebound, followed by five straight points with less than three minutes left, gave Notre Dame a 52-43 lead. "We defensed every positon well except Tracy," JMU Coach Lou Campanelli said.

"We've never played against a guard who crashed the boards like Jackson," JMU center Dan Ruland said. "Our guards didn't quite know how to block him out effectively."

Still, Steve Blackmon and Campanelli insisted the team held its own rebounding (a 28-25 Notre Dame edge), but lost the game by missing good shots in the second half.

But the unheralded Dukes, the ECAC South champion in their first Division I postseason tournament, weren't disappointed. They upset Georgetown Thursday night and had most of the packed Civic Center rooting for an even bigger upset today.

"There's some value in losing like this to Notre Dame," Campanelli said. "We did well here."