Brooks coached the Kings to a victory over Denver, where he was an assistant the previous three seasons under George Karl.
Kevin Martin scored 28 points and Brooks took home a souvenir game ball signed by the Kings after a 94-87 victory over the Nuggets.
Brooks appeared to be calm, staying on his feet for much of the game but showing much less emotion than Musselman, who was serving the first of a two-game suspension for driving under the influence.
"The butterflies were definitely all over the place," said Brooks, who was winless in four games while subbing for Karl. "I might have been looking cool, but it was an act, trust me."
Playing without the injured Allen Iverson and with a weary Carmelo Anthony, the Nuggets lost for the 20th straight time at Arco Arena, where they have not won in more than 10 years. The losing streak is the longest in the NBA, dating to Jan. 7, 1997.
"I can't pinpoint it, it's one of those tough arenas that we always have a lot of trouble in," said Marcus Camby, who had 15 rebounds and seven blocks. "Tonight I felt we could have got this one, but we just had way too many turnovers that cost us down the stretch."
Ron Artest was a major factor at both ends of the court. He had 21 points, 11 rebounds, five assists and four steals. His 3-pointer with 17 seconds left gave the Kings a 92-87 lead after Denver had crept to 90-87 on consecutive 3-pointers by Steve Blake and J.R. Smith.
But Artest might have been more valuable at the defensive end. Anthony, the NBA's leading scorer, was bothered all game by the pestering defense of Artest.
Coming off a season-high 46 minutes in Friday night's overtime win in Portland, Anthony shot 7-of-25 and had 20 points, seven rebounds and six turnovers.
"Ron did a heck of a job on Carmelo," Kings guard Mike Bibby said. "We got stops when we needed to in the fourth quarter and Ron hit that big shot at the end."
Anthony made no excuses for his subpar game.
"We missed a lot of layups, especially me," he said. "I missed a lot of tips around the rim.There were some times where I thought I could have made some shots. They played great defensively."
"He (Brooks) was nervous, you could tell he had the butterflies, so it was nice to get a win for him," Williamson said.
Nene had 13 points and 10 rebounds for Denver. Blake and Smith each scored 13 points, while Linas Kleiza added 10.
Denver opened the fourth quarter with a basket by Kleiza, pulling to 72-71. But the Nuggets, who shot 38 percent, scored just 19 points in the final period and never got any closer in losing for the fifth time in six games.
Martin scored 15 first-half points for the Kings, who closed the second quarter with a 20-6 run and led 53-43.
- Iverson missed his third straight game with a sprained right ankle.
- Anthony was 6-of-18 in 20 first-half minutes.
- The Kings have been outrebounded in 16 of 18 games.
- Artest stole the ball off the dribble twice from Anthony in the first half.