Harris scored 14 points with eight rebounds as he donned the Philly jersey for the first time since his trade deadline day move.
The star was traded by the LA Clippers with just hours to go on Thursday, along with Boban Marjanovic, who joined him in Philadelphia.
The move turned the 76ers into one of the most feared rosters in the NBA, as he teamed up with Jimmy Butler, Joel Embiid, JJ Redick and Ben Simmons.
The Nuggets went into the game just two games behind Western Conference leaders Golden State Warriors, but were beaten convincingly by the 76ers.
After the 76ers dashed into a 33-23 lead at the end of the first quarter, the Nuggets flipped the score in the second, going into half time at 56-56.
But in the second half, Philadelphia turned on the style and outscored Denver in the third and fourth quarters.
Speaking after the game, Harris praised his new team-mates and new fans.
“Nothing short of blessed. I truly am,” he said.
“To be able to come into a new home, to beat a great team, to do it with my team-mates, get off to a good start, it feels great.
“I am truly blessed, I couldn’t ask for no more.”
Harris’ acquisition formed a new ‘big four’ in Philly, and the 26-year-old explained that he is confident of building a formidable force in the Eastern Conference.
“[Team-mates are] Heck of basketball players,” he continued.
“Guys that know how to play, very talented, they’re a talented group.
“You saw in pockets of the game how good we can be.
“I think that’s a good thing, though, how much growth can be made.
“It was very energetic, all night energy shown, I was sat on the bench thinking our fans are the best, they give us that juice.
“I’m looking forward to playing many games in front of them.”