Harris contributed 14 points and seven assists in just 24 minutes on a night when fellow guard Monta Ellis struggled to find his best form.
"He's been going better and better each game," Carlisle told Dallas News. "He's getting more rhythm and more feel.
"On a night when Monta couldn't get it going, it was a godsend to have a guy like Devin. And he's smart. He knows what we need."
The 30-year-old recently returned to action after recovering from a foot injury.