BOSTON — Ray Allen found his shooting touch just in time to put the Boston Celtics within one win of the NBA finals for the first time since the original Big Three.

Allen scored 29, hitting a long 2-pointer after Detroit came within one point with a minute left, then he and Kevin Garnett each made a pair of free throws down the stretch as the Celtics beat the Detroit Pistons 106-102 today to take a 3-2 lead in the Eastern Conference finals.

Garnett scored 33 — his most in the playoffs this year — Kendrick Perkins had 18 points and 16 rebounds, and Rajon Rondo added seven points, 13 assists and six rebounds for Boston.

Game 6 is Friday in Detroit, and with a victory there or on Sunday back in Boston, the Celtics would advance to the NBA finals for the first time since Larry Bird, Kevin McHale and Robert Parish took them there in 1987.

Chauncey Billups scored 26 and Richard Hamilton had 25 points for Detroit, which has reached the conference finals six consecutive years but advanced further just twice and won one title in that span.