Paul Pierce drove into the lane late in the second quarter, absorbed some contact and scored on a finger-roll layup.
There was nothing remarkable about the play except for what happened next, the Clippers veteran forward landing awkwardly after it appeared his right leg was pinned beneath him when he fell.
Pierce clutched his right leg, writhing in anguish as he rolled over on the court. The crowd groaned when replays where shown on the scoreboard.
Three games before Blake Griffin is due to return from a layoff of more than three months, his replacement went down Monday night at Staples Center.
There was widespread concern that it might have been the end of a Hall of Fame career, though Pierce appeared to avoid serious injury during the Clippers' 114-90 thrashing of the Boston Celtics.
The team announced Pierce had sustained only a sprained right ankle and a bruised right knee, sparing him the cruel fate of having his last game end this way against the team he had long starred for and led to an NBA title.
"Of course, the Laker fans thought they were going to bring out a wheelchair at one point," Doc Rivers joked, referring to Pierce's infamous in-game return during the 2008 Finals.
The Clippers hardly seemed undermanned after Pierce's departure. Chris Paul and DeAndre Jordan notched double-doubles in only three quarters and six players scored in double figures to lead the Clippers (46-27) to a third consecutive victory.
Paul finished with 13 points and 14 assists and Jordan had 15 points and 13 rebounds. It was the second consecutive game Rivers was able to rest his starters the entire fourth quarter.
The Clippers reserves outscored the starters, 67-47, with Austin Rivers (16 points), Jamal Crawford (15), Wesley Johnson (11) and Jeff Green (10) reaching double figures.
"All those guys really put pressure on their defense and were really good tonight," Jordan said. "Jeff — I mean 'Buckets' — came down and knocked down a couple of shots. He likes it when you call him 'Buckets.' The guys were just playing with high confidence."
Isaiah Thomas had 24 points for the Celtics (43-31), whose fans announced their presence in the game's opening minutes when Thomas chased down Paul on a breakaway and blocked his layup. Paul picked up a technical foul less than a minute later.
The vibe turned in favor of the home team when the Clippers reserves sparked a 13-1 run in the second quarter. The Clippers led by as many as 18 points as Paul reached his double-double with 13 points and 11 assists before halftime.
None of that seemed to matter when Pierce drove for his final layup, Boston's Jared Sullinger making contact with him on the play.
"For a second, when he grabbed his knee, I definitely thought, 'Oh boy,'" Doc Rivers said. "And, then, I'm thinking, 'Against the Celtics . . . ' I was thinking, 'No.'"
Paul and Clippers trainer Jasen Powell helped Pierce off the court before he walked to the locker room under his own power. He was universally cheered, the Boston fans mindful a Celtics career in which he logged 1,102 regular-season games and 24,021 points.
Doc Rivers said he was relieved the primary injury was to Pierce's ankle and not his knee. It appeared otherwise when Pierce initially grabbed his knee, but Rivers said he had absorbed knee-to-knee contact and nothing more significant.
Pierce finished with eight points, three rebounds and two assists in 11 minutes in what might have been his final appearance against his former team even if he is able to play again this season. The 38-year-old has said he will decide this summer whether to return for a 19th NBA season.