The Celtics, who were expected to fade from the post-season picture when Rondo went down with a season-ending knee injury, have instead gone on a storming run, with all five of their victories coming since the All-Star guard was hurt.
Garnett has been the subject of persistent trade rumours as the February 21 deadline approaches but it appears increasingly unlikely that he will be leaving Boston as the Celtics (25-23) tighten their grip on a play-off berth.
Led by Garnett, all five starters reached double figures as Courtney Lee chipped in with 15 points, Leanadro Barbosa added 14 off the bench and Paul Pierce contributed 12 points along with 11 rebounds.
"We are fighters, we are a team that is going to fight for 48 minutes," Garnett said. "It's not always pretty, we are not perfect and we are human but we play hard.
"With Rajon going out, Paul (Pierce) and I really have to facilitate the responsibility of being leaders out there."
The night began with the Celtics holding the eighth and final playoff spot in the Eastern Conference and the Raptors 7 1/2 games back in 11th and desperate to cut into Boston's advantage.
The addition of Rudy Gay and the return of Andrea Bargnani should eventually aid in that effort but they were unable to make a winning impact on Wednesday.
Gay has been an instant success since being acquired in a trade with the Memphis Grizzlies, leading the Raptors (17-32) in all three games he has played, including a 25 point-12 rebound effort against the Celtics.
Bargnani, who had sat out 26 games recovering from torn elbow ligaments and a strained wrist, showed a little rust in his return to action but the big Italian still made a solid contribution, collecting 13 points in nearly 24 minutes of work.
"For eight weeks I was unable to shoot so I definitely need to get back in the rhythm, get back in shape," said Bargnani, the number one overall pick in the 2006 NBA draft. "I have to keep working.
"Being out so many weeks I've got to play harder on the defensive end."
The Raptors had brought the Air Canada Centre crowd to life when they went on 10-2 run to close out the third quarter with a 77-69 lead.
However, the Celtics responded with a 10-0 run of their own to erase the deficit as Barbosa and Garnett led the fourth quarter charge with 12 and 11 points respectively.
"They're champions and there's a reason," Raptors coach Dwane Casey said.
"They know how to finish games and we are going to have to learn that way because that's how you play playoff basketball... grabbing, holding, hitting first, the ability to draw fouls all those things are what make a championship team.