The 2019 NBA Draft top overall pick scored 21 points, shooting nine-of-17 from the field, with 12 rebounds and seven assists in the Pelicans' 112-91 win over the short-handed Los Angeles Clippers.
Williamson had missed the Pelicans' past two games after suffering a posterior hip contusion in a heavy fall following a dunk attempt in their loss to the Utah Jazz last Sunday.
"Glad to have him back," Green said. "When he touches the ball - I've said it before - he makes the right play. Whether it's a score for himself or finding his teammates and kicking it out and continuing to move. He was fantastic."
Williamson missed all of last season with a broken foot having developed into an All-Star in his second season in 2020-21, averaging 27 points, 7.2 rebounds and 3.7 assists.
The Pelicans power forward is averaging 22 points, 6.7 rebounds and 2.3 assists across four games this season as he works his way back.
New Orleans have started the season 4-2 and loom as a danger side in the Western Conference with Williamson in full flight and he said he had developed his offensive game since his All-Star year.
"I would say before, I think I would rush it sometimes trying to see the open pass," Williamson said. "But now I just let it develop. I let the defense kind of shift towards me as soon as I see them take that shift.
"We got some special shooters on this team, and I'm able to find them and they knock the shots down."
Williamson also reassured that he was feeling better, albeit sore, after his hip injury.
"Still a little sore, man," Williamson said. "I've taken a lot of falls, but I ain't never had a fall like that one. But it was fine enough for me to play.
"Unless I'm truly injured, I'm going to be playing the game of basketball. That's just how I am."