Davis' monster points haul, which is the second most by a player in a single NBA game this season behind Joel Embiid's 59, backed up Friday's 44 points against the Milwaukee Bucks. Davis is the first Laker with back-to-back 40-point games since Kobe Bryant in March 2013.
Davis fell just shy of his career-high 59 points in a single game, but it was the second most he has ever scored and most for the Lakers.
"He's been unbelievable, man," James told reporters. "On both sides of the floor. I mean, playing like the MVP of this league. Just straight dominance."
The Lakers power forward is averaging a career-best 12.6 rebounds this season, along with 27.2 points and 2.4 blocks.
"I just think he's hit a switch where he knows how dominant he can be, night in, night out," James said.
"He's got every aspect of his game working right now. From the paint, to the mid-range, to the threes, his free-throws, his jump hooks, he has everything working for him right now.
"It's just the work. When you put in the work, you live with the results."
Davis' near career-best season comes after injuries dogged him over the past two years, restricting him to only 76 games across the past two seasons.
James said eight-time All-Star Davis had re-discovered his confidence in both his body and his play, admitting he had kept in his ear to get the best out of his team-mate.
"We all need to be reminded sometimes, no matter how good you are sometimes," James said. "Why you're here, what your capabilities are and how much we believe in each other.
"Me as the leader of the team, it's part of my job to reassure AD how great he is in this league, not just this team."