Together, the Pacers' tag-team inside tandem simply overpowered the Celtics.
''He (West) is our backbone. He's the one that lifts us and he's our best late-game playmaker and shot maker,'' Paul George said. ''We always rely on David and he always digs us out of holes.''
The Pacers desperately needed West's closing punch after losing a season high four straight.
They also needed Bynum's presence.
George wasn't the only having trouble Tuesday.
Indiana's other big perimeter shooter, Lance Stephenson, went 4 of 12 from the field and was shut out in the first half. Starting point guard George Hill appeared to hurt his right hand in the fourth quarter and All-Star center Roy Hibbert finished the game despite a hard fourth-quarter fall.
Yet the re-emerging West and Bynum, who played for the first time in almost 2½ months, made up for those problems.
''I felt great. I couldn't do anything wrong today,'' Bynum said. ''All the rebounds came my way. I just grabbed them.''
The win gives Indiana a 1½-game lead over Miami in the Eastern Conference standings. The Pacers also became the first team to win 30 home games and are still a league-best 30-4 at Bankers Life Fieldhouse.
While West stole the show on the court, Bynum created the most buzz off of it.
For six weeks, Pacers fans waited to see No. 17 take the court. The 7-foot former All-Star drew a rousing ovation when he entered with 4:22 left in the first quarter and by the time the period ended, Bynum already had four points, five rebounds and one assist.
Afterward, Bynum downplayed the impact he had.
West, however, thought Bynum's presence made a huge difference -- one that could help Indiana get back on track and stay on track through June.
''He had an opportunity and he took advantage of it tonight,'' West said. ''He's going to make the game simple from my perspective when he's on the floor. We've got to play through him offensively. He's solid.''
Jared Sullinger led Boston with 17 points and nine rebounds, Kris Humphries added 15 points, but it wasn't enough to win a third straight as the Celtics lost more ground in their chase to make the playoffs.
And even though the Celtics twice got within one point of the Pacers in the fourth quarter, first-year coach Brad Stevens contended the Pacers recent struggles were nothing compared to what most other NBA teams face on a nightly basis.
''They're 47-17, right? They ain't got no troubles,'' said Stevens, who left nearby Butler to take the Boston job last summer. ''I know we've got to make a story out of something, but it's really not. And I've lived it on the other side where you're almost over cynical to a really good team and that becomes hard, too. The challenge becomes to continue on and not get too down or too high and they're good at it.''
As well as Bynum and West played at times Tuesday, the Pacers still struggled to put this one away.
Bynum's first basket, a dunk, broke a 14-14 tie and the Pacers never trailed again.
Indiana led by as much as 14 in the second quarter and was up 49-40 at the half. The Pacers rebuilt a 65-50 lead late in the third quarter before the Celtics rallied.
They got to 69-61 after three, closed to 69-66 early in the fourth and then got as close as 77-76 when Sullinger scored with 6:44 left.
''We finally got a couple of baskets without interference late in the game,'' Stevens said. ''But those are hard to come by against these guys.''
West answered with a 21-foot jumper, Stephenson scored on a layup, Hibbert knocked down a 19-footer and the Celtics couldn't get closer than five.
''We've still got a lot of work to do,'' West said. ''We've got to get back to playing our style of basketball, being aggressive and playing with a little more confidence.''
The Pacers pulled off their first four-game sweep of Boston since 1997-98.... The Celtics are now 2-14 on the first night of back-to-backs this season. ... Stephenson and George had a combined four points through the first 2½ quarters. George finished with 12, Stephenson with nine.