Kevin Garnett threw down an emphatic dunk, then grimaced before he even landed.

With that, Boston's smooth run through this NBA season came to an end.

Garnett left in the first quarter with a leg injury, and the Celtics looked ragged without him in a 104-92 loss to the Detroit Pistons last night in Auburn Hills. Boston lost for only the second time in 17 games, but the Celtics are suddenly facing some adversity they hope isn't too serious.

"It is a muscle injury, not a knee," Boston coach Doc Rivers said. "You always worry when a guy goes down without anyone around him, because those always seem to be severe injuries, so that was the first thing that went through my mind. We don't think this one is too bad, but we'll see. He'll probably miss some time, and we'll have to adjust."

Tracy McGrady - himself no stranger to leg problems - scored a season-high 21 points for the Pistons. He also played over 30 minutes for the first time since March.

Detroit led 45-37 at halftime and pushed the margin to 16 in the third quarter.

Boston played without point guard Rajon Rondo, who missed his sixth straight game with a sprained left ankle. The Celtics have been able to win without him, but it was a struggle from the start against the Pistons.

When Garnett dunked for his only two points of the game, he had a pained look on his face before he landed and was careful to avoid putting too much weight on his right leg. After intentionally fouling to stop the game, he went down to the ground momentarily and appeared distraught when he got up, at one point covering his face with his hands. He was able to hobble off the court but was limping badly by the time he got back to the locker room.

X-rays revealed no fracture, but he was done for the night and possibly longer.

"I think Kevin's injury took a lot of wind out of our players, because we originally thought the injury was a lot more severe than it turned out to be," Rivers said. "I think there was a while there where our minds weren't where we needed them to be."

Paul Pierce scored 33 points for the Celtics, but he was fighting a losing battle on this night.

In other games:

* At Charlotte, N.C., Stephen Jackson scored 38 points, D.J. Augustin added 28 and the Bobcats moved to 2-0 under interim coach Paul Silas with a 101-92 victory over the undermanned Cleveland Cavaliers.

* At Washington, Nick Young had 25 points and nine rebounds to lead the Wizards to a 104-90 win over the Indiana Pacers.

Wizards head coach Flip Saunders missed the game to be with his ailing mother.

* At Atlanta, Josh Smith had 22 points and 10 rebounds, Al Horford had 21 points and 15 rebounds and the Hawks beat the Golden State Warriors, 103-93.

* At Minneapolis, Chauncey Billups scored 15 of his 36 points in the fourth quarter, hitting three huge three-pointers to keep the Minnesota Timberwolves at bay and lift the Denver Nuggets to a 119-113 win.

_ At New Orleans, Lamar Odom responded to his first time out of the starting lineup this season by scoring 24 points, and the Los Angeles Lakers convincingly ended a three-game losing streak with a 103-88 victory over the Hornets.

_ At Oklahoma City, Kevin Durant scored 27 points before taking the fourth quarter off and the Thunder rolled past the error-prone New Jersey Nets, 114-93.

* At Houston, Dwyane Wade scored 45 points and the Miami Heat extended its road winning streak to 10 games with a 125-119 win over the Rockets.

Wade shook off a hard foul from Aaron Brooks early in the fourth quarter to reach 40 points for the 30th time in his career.