Dwyane Wade Parties with Justin Timberlake After Final NBA Game

Dwyane Wade's NYC retirement party turned into a good Bye-Bye-Bye Bash Wednesday night ... when Justin Timberlake and Jessica Biel stopped by to celebrate D-Wade's career!

The party was crazy -- a '70s-themed rager at Catch NYC with costumes and great music and basketball stars ... including Wade's good friend, Carmelo Anthony!

TMZ Sports obtained video from inside the party where you can see D-Wade, Gabby and Justin all gettin' down on the dance floor!!

Earlier in the evening, Wade posted a triple-double as the Miami Heat lost to the Brooklyn Nets 113-94.

A ton of Wade's friends were in the Brooklyn crowd -- including LeBron James, Carmelo and Chris Paul ... the entire Banana Boat crew.

Wade also gave his jersey to Carmelo after the game.

So, this is it ... Wade has finally closed the book on his 16-year NBA career that features 3 NBA championships, an NBA Finals MVP, 13 All-Star appearances, he won an Olympic gold medal for Team USA and he was also the NBA scoring champ in 2009.

He was also named to 8 All-NBA teams during his run.

So, what's next for Dwyane? Dude's got options in everything from fashion to TV announcing to acting ... and also helping his superstar sons as they get ready to play at the college level.