Brooklyn Nets guard Kyrie Irving has been fined $50,000 (£38,000) by the NBA for "making obscene gestures on court and directing profane language to the stands" in their opening play-off game against his former side.
The incident occurred during the Nets' 115-114 defeat at the Boston Celtics on Sunday.
The Boston crowd constantly booed 30-year-old Irving who was a former player of the club, and he responded by swearing and raising his middle finger.
Irving spent two years in Boston before an acrimonious departure following a fallout in 2019.
Irving, who scored 39 points at TD Garden, defended his actions after the game, saying: "It's nothing new when I come into this building [in terms of] what it's going to be like - but it's the same energy they have for me, I'm going to have the same energy for them.
"It's not about the fans - the fans aren't playing."
The Nets will hope to even their best-of-seven series when they play game two in Boston on Wednesday.
