BOSTON — The Boston Celtics advanced to the Eastern Conference finals with a 94-85 victory over Cleveland in Game 6 on Thursday night, sending LeBron James and the Cavaliers into an early offseason destined to define the future of the franchise — and the rest of the NBA, too.

The LeBron watch began at 10:53 p.m., when Rajon Rondo dribbled out the last 14 seconds and the Celtics began celebrating. James is eligible to opt out of his contract this summer, a move that would make the two-time MVP — and zero-time NBA champion — a free agent and set off a scramble for his services from New York to Miami to Los Angeles and, of course, back in Cleveland.

Kevin Garnett scored 22 points and added 12 rebounds, and Rondo had 21 points and 12 assists for Boston, which will open the conference finals in Orlando on Sunday. The Magic are 8-0 in the playoffs after sweeping the Charlotte Bobcats and the Atlanta Hawks in the opening rounds.

"Well we know their team is fueled by one guy," Garnett said. "If we could somehow, some way, control the supporting cast we had a chance"

James scored 27 points and had 10 assists and a career playoff-high 19 rebounds. Mo Williams scored 20 of his 22 points in the first half for the Cavaliers, who won an NBA-best 61 games in the regular season to earn a home-court advantage they never got to use.