The point guard scored a season-high 25 points for the team during their 104-95 win over the Boston Celtics, which ended his nine-game absence with a sprained ankle.
The small forward, who was also returning from an injury, told reporters: "He's the head of the snake. I mean he's one of the most important pieces of what we're trying to do here, what we're trying to build and trying to win a championship.
Williams added: "We're starting to get whole and it's definitely good to have everybody back. Even though Paul didn't start, I thought he came in and gave us a big boost off the bench.
"It seemed like our energy level was a lot better. More intensity on both ends of the floor."
The Nets play again tomorrow against the Los Angeles Clippers.