Paul Pierce is opening up on the most terrifying experience of his life ... revealing his near-fatal stabbing in 2000 shaped him into the man he is today.
The Celtics legend reflected on his past in an emotional conversation on Monday night's episode of Fox's celebrity competition show, "Stars On Mars" ... explaining the Boston nightclub incident -- in which he was stabbed 11 times -- completely changed his point of view.
"I've showed endurance in my life because I never gave up," Pierce said in the clip.