After a pair of Mo Williams free throws with 30.9 seconds left capped a 7-0 Blazers run to knot the score at 91-apiece, James made amends for a pair of turnovers on the previous two Miami possessions by driving left and converting a contested layup with 11.4 seconds showing.
The Blazers chose to play it out without calling a timeout and put the ball in All-Star Damian Lillard's hands. As the clock trickled down, Lillard put a move on a Miami defender and got to the rim, but Chris Bosh was there to deny his scoop layup at the buzzer.
Bosh finished with 15 points on his 30th birthday and Chris Andersen added 13 points with 11 rebounds off the bench as Miami completed the season-sweep of the Blazers.
Lillard paced Portland with 19 points, Williams chimed in with 17 points and Wesley Matthews scored 15 for the ailing Blazers, who were once again without star LaMarcus Aldridge (back). The Blazers fell to 0-2 on their current five- game road trip.