Rondo was running along the baseline toward the Toronto bench midway through the third quarter, when he hit the left elbow of Greivis Vasquez coming from the opposite direction. Rondo was attended to by trainer Ed Lacerte before retreating to the locker room to be stitched up.
Rondo returned with eight minutes to play and helped Boston rally from what had been a 15-point deficit, but the Raptors kept the Celtics at arm's length while emerging with a 99-90 triumph.
"It's just adrenaline going," Rondo said. "I just wanted to play."
Rondo finished with nine points, 15 assists, four rebounds, and two steals over 31:58. He said he knew he'd be able to return to game action.
"I didn't feel like I had a concussion or anything," he said. "They asked me a couple questions. That was just about it. I got them right, because I know they're pretty cautious. A couple people didn't want me to go back out there."
Rondo noted his competitive nature and desire to win the game encouraged him to return. That wasn't lost on coach Brad Stevens.
"I think it obviously says a lot. He wants to play," Stevens said. "Not only that, I think the most important part about it is he came back in and guarded (DeMar) DeRozan. He went after it and I thought he did a pretty good job on him. I'm going through my mind all the plays that we had that we could have taken advantage of that game and he was in the center of a lot of them."