The Boston Celtics, who built a tradition based upon postseason excellence, face the possibility of their earliest playoff exit in 33 years.

The Celtics suffered a 102-95 setback to the Detroit Pistons Sunday to trail 2-0 in the best-of-five, opening-round series. They could be eliminated Tuesday when the series switches to Boston Garden.A loss would mean first-round elimination for the first time since 1956 - the year before Bill Russell joined the team. Boston has won 16 NBA championships since 1957 and failed to make the playoffs only four times (1970, 1971, 1978 and 1979).

The main culprit in the Celtics undoing Sunday was Isiah Thomas, playing despite throbbing pain in his left hand due to a broken second metacarpal bone. The Detroit point guard sank 2 free throws with 25 seconds to play that sealed the victory.

Thomas finished with 26 points - the most he scored since suffering the injury April 7 in a fight with Chicago's Bill Cartwright. He scored 14 in the third quarter when Detroit trailed by 9.

"I think it was Isiah Thomas night, or day, whichever it was," Boston Coach Jimmy Rodgers said. "It was Isiah Thomas who really put together a string of great plays. He's always been a thorn in our side."

Kevin McHale's lone free throw with 2:18 left made it 96-93 and ended a 3:45 span in which neither team scored. Boston missed its last 12 shots from the field.

The Pistons, whose many strengths include a deep bench and a stifling defense, shut down McHale. Boston's main offensive threat was limited to 13 points on 4 of 13 shooting from the field.

"For an eight- or nine-minute period, I wasn't touching the ball on offense because we weren't getting it inside," McHale said.

Larry Bird was reportedly cleared to play in Game 3, but Rodgers said, "I would doubt it. We'll have to see what the doctors say. We didn't anticipate using him in the first round."

Mark Aguirre backed Thomas with 21 points while Vinnie Johnson added 18 and Joe Dumars 13. Boston recieved 25 points from Robert Parish, 21 from Reggie Lewis and 20 from Brian Shaw.

Cavaliers 96, Bulls 88

At Richfield, Ohio, Ron Harper scored 31 points, including a team playoff record 21 in the first half, to help Cleveland even its series 1-1. Michael Jordan scored 30 and dished out 10 assists for the Bulls, but committed 7 turnovers. The series resumes in Chicago for games 3 and 4 Wednesday and Friday.

Lakers 113, Blazers 105

At Inglewood, Calif., Magic Johnson scored 35 points and Los Angeles capitalized on Clyde Drexler's early foul trouble to move to within one victory of their sixth straight first-round sweep. The Lakers lead the series 2-0 and are undefeated in their last 17 first-round games dating to 1984.

Drexler, who finished with 28 points, had three fouls in the first four minutes. Game 3 is Wednesday at Portland.

Sonics 109, Rockets 97

At Seattle, Xavier McDaniel and Alton Lister scored 20 points apiece to lead Seattle to a 2-0 series lead. With the Rockets concentrating on stopping Dale Ellis and McDaniel, the Sonics involved more players on offense. Reserves Michael Cage and Sedale Threatt both scored 16 points for Seattle.

Akeem Olajuwon finished with 30 points and 12 rebounds for the Rockets. The series switches to Houston for Game 3 Wednesday.

Suns 132, Nuggets 114

At Phoenix, Kevin Johnson scored 34 points and handed out 14 assists to power Phoenix to a 2-0 series lead. Johnson's 14 assists and 18 for 19 performance from the free throw line were Phoenix team records for playoff games.

Tom Chambers had 24 points, Eddie Johnson 21 and Jeff Hornacek and Dan Majerle added 17 apiece for Phoenix. Alex English led Denver with 36 points, and Michael Adams had 25 for the Nuggets, including 6 three-point goals which tied the NBA record for playoff games.