Bosh, who hit the go-ahead shot in Game 3 to give the Heat a 2-1 series lead,
went 5-for-5 in the second quarter for 10 of his points.
Dwyane Wade added 13 points for the Heat and LeBron James scored just four.
Dirk Nowitzki had eight points for the Mavericks while DeShawn Stevenson
scored 11 despite being replaced in the starting lineup by J.J. Barea.
Stevenson had three three-pointers and scored all of his points in the second
Mavericks backup center Brendan Haywood was activated after missing Game 3
with a right hip flexor injury and played just over three minutes in the first