Dwyane Wade added 21 points and 12 assists, Michael Beasley, who was cut by the Suns in the offseason, threw down an alley-oop dunk among his eight points. Ray Allen scored nine of his 17 points in a fourth quarter.
Mario Chalmers sat out due to a strained hip flexor.
Channing Frye led the Suns with 16 points and eight rebounds, Goran Dragic contributed 14 points, nine assists and eight boards but knew his team efforts were futile.
“They have so many weapons,” Dragic said of the Heat. “They have a feeling they can do anything.”
The Suns were pumped coming off their two consecutive road wins over Charlotte and Orlando, and kept it a game early on with Miami gaining the respect of The Heats’ head coach Erik Spoelstra.
“We had to work for this one,” Spoelstra said. “They’re a good, young basketball team.”
The Suns were unable to halt production of the Heat’s supporting cast, which led to Chris Andersen being able to score most of his points on layups or putbacks and Allen, Beasley and Shane Battier able to score faily unchallenged. James and Wade combined to shoot 20 of 27 from the field.