The Celtics led 96-80 with 5:09 left in the game, but the Blazers went on a 15-point run that closed the gap to one point in the final minute — until Paul Pierce  found Allen in the corner.
Pierce netted a game-high 28 points to go along with seven rebounds, as the Celtics improved 14-4 on the season. Kevin Garnett  (17), Glen Davis  (16), Shaquille O’Neal  (14) and Rajon Rondo  (10) also reached double digits in scoring.
WHAT WENT RIGHT
Pierce asserted himself: With the Celtics trailing by as many as 11 points in the first half, Pierce took action — creating offense for himself. A nifty driving layup as he faked two defenders got him going, jumpstarting a 10-point second quarter, including a pair of 3-pointers that got the C’s back into the game.
Pierce didn’t miss his first shot until five minutes remained in the third quarter. In all, he finished with 28 points on 9-of-11 shooting (4-of-5 from 3-point range).
Big Baby buries jumpers: In a span of 2:49, Davis scored eight straight third-quarter points — including three 20-foot jump shots — to help the Celtics stay within striking distance of the Blazers. He scored 16 points on the night on 7-of-9 shooting.
Combined, Pierce and Davis scored 20 of the Celtics’ 31 third-quarter points, leading an otherwise stagnant offensive effort and giving the C’s a seven-point cushion entering the fourth quarter.
Shaq showing hustle: O’Neal turned in another solid performance. Running the floor throughout his 26 minutes, he totaled 14 points on 5-of-7 shooting, and he even made four of his six foul shots. His rebounding could’ve used some work, though, as he finished with just four boards on the night.
WHAT WENT WRONG
Too many turnovers: How could the Celtics shoot 61 percent from the field while holding the Blazers to 45 percent shooting and still trail by one at the half? One word: Turnovers.
In the first quarter alone, the Celtics committed seven turnovers, including careless traveling violations on consecutive possessions by Garnett and Pierce. Meanwhile, the Blazers turned the ball over just twice in the first 12 minutes, taking a 26-20 lead into the second quarter.
In all, the Celtics committed 17 turnovers, resulting in 19 Trail Blazers points.
Wesley Matthews happened: Shooting from pretty much everywhere on the court, Matthews shot a blistering 5-of-7 from beyond the arc (8-of-13 altogether), dropping 23 points on Allen and the Celtics.
On the other end, the stronger Matthews chased Allen around screen after screen, holding the Celtics shooting guard to just 2-of-11 shooting and six points — until Allen’s last-second 3-pointer that clinched the game.
Defensive rebounding: As if the Celtics’ 17 turnovers didn’t give the Trail Blazers enough extra possessions, Portland also collected seven offensive boards — including a putback dunk by LaMarcus Aldridge (18 points) that gave the Blazers an eight-point cushion in the third quarter. As a result, the Blazers outscored the Celtics 42-38 in the paint.