Tristan Thompson has obtained a legal victory.

The Cleveland Cavaliers player has been granted temporary guardianship of his younger brother Amari Douglas Thompson, 17, according to court documents obtained by E! News on Sept. 21. The temporary guardianship will run until Dec. 5, 2023.

The legal move grants Tristan, 32, all the powers a parent having legal custody of a child would have, such as managing Amari's finances, traveling with him both in the U.S. and internationally, applying for American citizenship, deciding living arrangements and obtaining legal counsel.  

Tristan filed for temporary guardianship on Sept. 8 following his mom Andrea Thompson's unexpected death from a heart attack in January. Andrea, who lived in Toronto, was 53.

In the wake of Andrea's passing, Khloe Kardashian—who shares daughter True Thompson, 5, and 13-month-old son Tatum Thompson with Tristan—stood by the athlete's aside to "comfort and help him navigate what will be a very difficult time," a source told E! News at the time.

"She was incredibly close to his mother, and like Khloe and the Kardashian family always do, they will come together and support their loved ones in their most difficult time of need," the insider shared. "Tristan is the father of Khloe's kids and she and her entire family will always be there for him."

Tristan brought Amari from Toronto to California; however, the NBA star's house became unlivable due to storm damage. As a result, Khloe shared in a July episode of the Kardashians that Tristan and Amari moved in with her.

"I'm grateful that I'm strong enough and brave enough to be a support system for someone else that has no other support system right now," Khloe said in a confessional. "You don't have to treat me right for me to treat you right—it's not the way I was raised."

Tristan also shares Prince Oliver, 6, with ex Jordan Craig and son Theo, 21 months, with Maralee Nichols.

For the latest breaking news updates, click here to download the E! News App