Pierce's dramatic return after being carried from the court and then wheeled down a hallway for treatment will be added to the annals of Celtics-Lakers lore, taking a spot alongside Magic Johnson's baby sky hook and Kevin McHale's clothesline of Kurt Rambis.
Kevin Garnett scored 24 points, Pierce finished with 22 - 11 after getting hurt - and Ray Allen, the third member of Boston's Big Three, added 19 for the Celtics, who are chasing a 17th NBA championship. The trio was making its first finals appearance, and for a short time it appeared only two of them would finish their long-awaited debut.
In the third quarter, Pierce was deep in the lane when teammate Kendrick Perkins crashed into him from behind, crumpling Boston's No. 34 to the court. The 10-year veteran, who last summer thought his days with Boston might be nearing an end, had to be carried from the court in extreme pain and was taken to Boston's locker room in a wheelchair.
"When I came down I thought I felt a pop, I thought I tore it," Pierce said.
The sight of Pierce leaving drew gasps from some Celtics fans. However, their worries were soothed just moments later when Pierce returned to Boston's bench and checked back in with 5:04 remaining. As Pierce jogged onto the court with a black elastic wrap on his knee, Garnett clinched a fist and screamed, "Yes!"
Soon, more than 18,000 others were screaming as Pierce made two 3-pointers in just 22 seconds to give the Celtics a 75-71 lead.
"When I got in the back I could put some weight on it," Pierce said. "I knew needed to be out there for my team."
Kobe Bryant led the Lakers with 24 points, but the regular-season MVP was just 9-of-26 from the field as the league's top defensive team kept close tabs on him. Bryant had numerous shots rattle out and spent most of his 42 minutes in the game searching for a rhythm.
Derek Fisher and Pau Gasol had 15 points apiece and Lamar Odom added 14 for the Lakers, who had won the first two games of their previous three series this postseason. Los Angeles will try to even the series in Game 2 on Sunday night.