Detroit reached the .500 mark and is 3-0 since Griffin joined the starting lineup. The five-time All-Star was acquired from the Los Angeles Clippers a week ago.
A handful of other Pistons also reached double figures. Andre Drummond racked up 17 points, 17 rebounds and five assists, and Anthony Tolliver scored 13 of his 15 points during the fourth quarter. Langston Galloway and Reggie Bullock supplied 13 points each, and rookie Luke Kennard tossed in 12.
"This is the perfect time for us to try to make our run, right before the All-Star break," Galloway said in a postgame TV interview. "A lot of teams are trying to separate right now, so we've got to keep battling, keep getting wins and finish out this stretch."
Damian Lillard's 20 points led the Trail Blazers, who lost on a buzzer-beating shot at Boston on Sunday. CJ McCollum had 14 points, Pat Connaughton added 11 and Jusuf Nurkic chipped in 10 for Portland.
The Pistons shot 50.6 percent from the field while holding the Blazers to 39.4 percent shooting. Detroit had a 51-44 rebounding edge and assisted in 36 of its 44 field goals.
Griffin scored 15 first-half points, including a layup in the closing seconds to give Detroit a 49-43 halftime advantage. Drummond and Bullock scored 10 points apiece before the break, while Napier led the Blazers with eight points.
The Pistons increased their lead to 75-57 with a 14-2, third-quarter run. Stanley Johnson scored five points during that stretch and Kennard capped it off with a 3-pointer.
Portland finished the quarter with a 10-4 spurt, including five points from Lillard, to make it 79-67 heading into the fourth.
The Blazers were unable to get the deficit under double digits. When Drummond hit two free throws with 6:56 remaining, Detroit's margin was up to 20 at 94-74.
--Field Level Media
Portland | Detroit | |
Damian Lillard 20 | Scoring | Blake Griffin 21 |
Damian Lillard 5 | Assists | Ish Smith 7 |
Al-Farouq Aminu 14 | Rebounds | Andre Drummond 17 |
Damian Lillard 3 | Free Throws Made | Andre Drummond 3 |
Al-Farouq Aminu 2 | Steals | Reggie Bullock 3 |
Jusuf Nurkic 2 | Blocks | Andre Drummond 3 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Portland | 91 | 39.4 | 10-33 | 7-8 | 18 | 45 | 5 | 9 | 13 |
Detroit | 111 | 50.0 | 15-30 | 8-12 | 36 | 51 | 4 | 7 | 14 |