The Boston Celtics signed Kyrie Irving from the Cleveland Cavaliers on Tuesday in a blockbuster trade that saw Isaiah Thomas head in the opposition direction, the Celtics confirmed.
The Celtics said they had acquired Irving in exchange for Thomas, forward Jae Crowder, centre Ante Zizic and the rights to the Brooklyn Nets' 2018 first-round pick.
"Kyrie is one of the best scorers in the NBA. He has proven that on the biggest stage, the NBA Finals, the last three years," Celtics President of Basketball Operations Danny Ainge said.
"He's been an NBA champion, an Olympic gold medallist, and a four-time All-Star. For all he's accomplished, we think his best years are ahead of him."
Celtics co-owner Wyc Grousbeck meanwhile paid tribute to the contribution of the departing Thomas and Crowder, key performers for Boston last season as they finished first in the Eastern Conference.
"Isaiah and Jae have been a huge part of our success," he said. "Isaiah's play-off performance under very difficult circumstances will live on in history, and we wish them all the best."
Jake Badger: Kyrie Irving's Cavs career
Irving's request for a move away from Cleveland and LeBron James stunned the NBA when it was confirmed in July.
The Cavaliers have made it to the NBA Finals in each of the last three seasons, beating Golden State once and losing on two other occasions.
The Celtics meanwhile topped the Eastern Conference last season but were beaten by Cleveland in five games in the play-offs.
Playmaker Thomas missed the last three games of the series after suffering a hip injury and is reportedly struggling to be fit for the start of the new season in October.
Irving, 25, who averaged 25.2 points on 47.3 per cent shooting and 5.8 assists last season, has three years and US$60 million (Dh220.3m) remaining on his contract.
Thomas, third in the NBA last season with an average of 28.9 points, will be a free agent after the 2017/18 campaign.