The buzz was there, almost every time rookie LeBron James touched the ball in the Cavaliers' 87-84 loss to the host Boston Celtics in their opening game in the Reebok Pro Summer League last night at the Clark Athletic Center at the University of Massachusetts.

It moved through the crowd like a current as James, who scored four straight baskets to get the Cavs within 45-34, headed downcourt dribbling the basketball late in the first half. But when he fired a pass Carlos Boozer couldn't handle, the jam-packed crowd of 2,500 in the steamy little gym let out a collective sigh that briefly stirred the air in the sauna-like arena.

James had 12 points in the first half, and he added only two in the third quarter. When he left the game with 2:32 left in the period, his departure barely created a ripple.

But coach Stephen Silas switched James from point guard to shooting guard in the fourth quarter, and early on the buzz was back. James had the ball on the right wing, facing the basket. He faked right, then spun left, drove hard to the hoop and threw down a tremendous dunk that turned the buzz into a full-throated roar. For the first time all night, the crowd of mostly diehard Celtics fans seemed to be on James' side.

"Crowds love highlights," said James, who finished with 25 points, nine rebounds, five assists, two blocked shots, two turnovers and a steal. He made 11 of 21 shots, 2 of 5 from 3-point range.

Boozer added 21 points, eight rebounds, two steals and a blocked shot.