After receiving a warm welcome from the home crowd, Pierce and Garnett both put forward relatively disappointing efforts, scoring six points apiece in the win.
However, it was Garnett's steal and layup with under 20 seconds remaining that sealed the game for Brooklyn. The Big Ticket finished with three rebounds, three assists and a steal, as well.
In one of the sloppiest offensive games of the year, the Nets and Celtics shot 39 and 38 percent from the field, respectively, and knocked down a combined 13 of 51 threes.
Andray Blatche led the Nets with 17 points on 6-of-15 shooting off the bench while Alan Anderson and Andrei Kirilenko each added 11 points.
Brandon Bass was tops on the Celtics with 17 points on a perfect 6-of-6 shooting, but it was Rajon Rondo who led the Celtics offense from start to finish with a season-high 13 points. Boston's point guard also threatened to post a triple-double with eight rebounds and eight assists in the loss.
The only other Celtics players to finish in double figures, Gerald Wallace and Chris Johnson scored 12 points apiece on a combined 8-of-14 shooting.
Next up for the Nets is a meeting with the Toronto Raptors on Monday while the Celtics are set for a showdown with the New York Knicks on Tuesday at Madison Square Garden.