Brad Stevens went primarily with the second unit in the second quarter and Jerryd Bayless shined against his former team finishing the half with 10 points on 5-7 shooting in 11 and a half minutes.
Portland, however, went on a run late in the half that Boston barely withheld going into the locker room.
Damian Lillard paced Portland with 13 points on 5-9 shooting.
Halftime: Celtics 60 Blazers 58
Avery Bradley came out hot once again after the break making his first three shots, yet, with little other production from the rest of the Celtics, Portland led 73-68 with 6:36 remaining in the quarter.
Eventually Sully got hot hitting three jumpers straight including a 3 as well as tipping in a ball to end the quarter cutting the Blazer lead to four going into the final frame.
Boston started out the fourth going with the second unit and cutting the Portland lead to 1 on a Bayless runner with 10:48 to play.
Alas, the C's second unit would struggle after that and the first unit could never close the gap as Portland went on a 6-0 run on their way to an easy 112-104 win.