Derek Harper's three-point shot with three seconds to play gave the Mavericks a 110-108 victory over the Los Angeles Lakers in their semifinal playoff series last night in Dallas. Forty-three seconds earlier, he had made another three-pointer.

The Lakers will take a 2-1 lead into Sunday's fourth game of the seven-game series at Reunion Arena.

Harper is the player who two years ago dribbled away the last seconds of a playoff game in Dallas, thinking the Lakers trailed.

"I hope this puts two years ago to rest," he said. "I've been able to joke about it. It was a mistake."

Kareem Abdul-Jabbar, playing a career record-tying 172nd postseason game, controlled inside for three quarters and gave the Lakers a 10-point lead late in the third period, but Dallas scored the last eight points to get back in the game.

Harper's three-pointer with 46 seconds left tied the game, but Los Angeles' Byron Scott made a three-point shot with 28 seconds to go.

Rolando Blackman of Dallas made a jump shot four seconds later and then, with 20 seconds to go, he fouled Michael Cooper. Cooper missed both foul shots and Dallas' Sam Perkins got the rebound. After a timeout, the Mavericks' Mark Aguirre bounced a shot off the rim. During a wild scramble under the basket, the ball shot out to Harper near the three-point arc. His shot swished.

*Celtics 111, Hawks 107: In Atlanta, the Boston Celtics savored the confidence that goes with a 3-0 lead in the NBA Eastern Conference final.

"I've been in the position before, and being down 3-0 is obviously not a good one," Boston's Larry Bird said. "There may be some team in the league that can beat us four straight, but I've yet to see one."

He had 28 points, nine rebounds and 12 assists for the Celtics, who can end the best-of-seven series Sunday in Atlanta.

Kevin McHale and Danny Ainge each had five points in the last 3 1/2 minutes after Atlanta had come within a point 44 seconds earlier.

"There is no reason to play any more games than we have to," said Ainge, who has been booed in Atlanta since a brawl with Tree Rollins in the playoffs two years ago.

*Nuggets 116, Rockets 115: In Denver, Alex English, rebounding from a playoff shooting slump, scored 33 points and sixth man Bill Hanzlik had 21 as the Nuggets edged Houston in a Western Conference semifinal. The victory drew the Nuggets within 2-1 in the best-of-seven series, with Game 4 to be held in Denver Sunday afternoon.

Akeem Olajuwon led Houston with 31 points; Ralph Sampson had 27.