The Milwaukee Bucks have boycotted Wednesday's NBA play-off game against the Orlando Magic in an apparent protest against racial injustice following the police shooting of Jacob Blake in their home state of Wisconsin last week.
Leading 3-1 and needing just one more win to move into the Eastern Conference semi-finals, the Bucks did not emerge from their locker room for practice ahead of game five.
The NBA subsequently postponed its two other play-off games scheduled for Wednesday night.
In other player-led responses to the shooting and accompanying unrest, three WNBA fixtures were also called off, as were two Major League Baseball games – one of which was due to take place in Milwaukee. Five of the six scheduled Major League Soccer games were also postponed.
Bucks senior vice president Alex Lasry wrote on Twitter: "Some things are bigger than basketball. The stand taken today by the players and org shows that we're fed up. Enough is enough. Change needs to happen.
"I'm incredibly proud of our guys and we stand 100% behind our players ready to assist and bring about real change."
Blake was shot on Sunday in Kenosha, Wisconsin – 40 miles from Milwaukee – apparently in the back and in front of his children, with the incident captured on phone video, igniting new protests over racial injustice in several cities
In light of Milwaukee's stance, the NBA announced Wednesday's matches between the Bucks and the Magic, as well as LA Lakers-Portland Trail Blazers and Houston Rockets-Oklahoma City Thunder, have been shelved.
A statement on its Twitter account said: "The NBA and the NBPA today announced that in light of the Milwaukee Bucks' decision to not take the floor today for Game 5 against the Orlando Magic, today's three games – MIL-ORL, HOU-OKC and LAL-POR have been postponed. Game 5 of each series will be rescheduled."
The Bucks, whose star man Giannis Antetokounmpo was named defensive player of the year this week, are among the favourites to collect only the second NBA championship in their history.
On the eve of game five, Bucks head coach Mike Budenholzer said in a press conference posted on the team's website: "Myself, our players and our organisation are very disturbed by what has happened in Kenosha.
"Our team has had lots of conversations and has a high level of concern and wants to continue to fight for racial justice, for social justice, for the end of excessive use of force by police.
"It's a great challenge to have an appreciation and a desire to want change and want something different and better in Kenosha and Milwaukee and Wisconsin, and then to go out and play a game."
A statement from the Magic said: "Today we stand with the NBA Office, the National Basketball Players Association, the Milwaukee Bucks and the rest of the league condemning bigotry, racial injustice and the unwarranted use of violence by police against people of colour."
The Lakers later tweeted "#JusticeForJacobBlake", while Los Angeles player LeBron James posted "WE DEMAND CHANGE. SICK OF IT".
Meanwhile, baseball matches between the Cincinnati Reds and Milwaukee Brewers in Milwaukee, and between the Seattle Mariners and San Diego Padres in San Diego, were also postponed.
"The players from the Brewers and Reds have decided to not play tonight's baseball game. With our community and our nation in such pain, we wanted to draw as much attention to the issues that really matter, especially racial injustice and systemic oppression," players from both teams said in a joint statement.
Mariners pitcher Justin Dunn tweeted: "Enough is enough."
The remaining Major League matches set down for Wednesday were in either progress or just about to start when the announcements were made.
The WNBA followed the NBA's lead by also postponing its three scheduled Wednesday matches.