LeBron James, left, has his headband knocked off by Washington's DeShawn Stevenson during the second quarter of Cleveland's Game 4 win on Sunday. Stevenson was charged with a flagrant foul on the play. (Pablo Martinez/Associated Press)

King James lost his crown.

All right, so it was his burgundy headband that went flying when LeBron James took a shot to the noggin from DeShawn Stevenson, their simmering feud nearly boiling over.

James kept his cool, allowing the flagrant foul to spark him and his Cleveland Cavaliers.

At game's end, James was just as collected, drawing waves of Washington Wizards defenders before dishing to Delonte West for a tie-breaking 3-pointer with 5.4 seconds left.

That shot, along with James's 34 points and 12 rebounds, led the Cavaliers to a 100-97 victory on Sunday and a 3-1 lead in their best-of-seven Eastern Conference playoff series.

"There's been some extracurricular activities going on outside and inside this series," James said, "but I've been able to stay focused."

The Wizards were ahead by a point with 3½ minutes left in the first half when James drove to the basket and Stevenson came from behind and swiped a hand out, clipping the Cavs' star with what appeared to be a closed fist before tumbling to the court.

James kept his balance and stepped toward Stevenson, who got up and stepped toward James.

They exchanged words, but that was it, before teammates stepped in between. "If we was on the park, something definitely would have escalated," James said. "But, you know, I guess that's what they want to do. They want to hurt LeBron James this series. It ain't working."

Stevenson's take?

"That's how it goes," he said. "It was a big game for us."

Now the Cavaliers, who eliminated the Wizards in each of the previous two postseasons, have control, with Game 5 on Wednesday at Cleveland.

James got help Sunday from more than just West, whose career playoff-high 21 points included five 3-pointers. Daniel Gibson made four treys, and Ben Wallace had 12 rebounds, part of a remarkable 51-31 edge on the boards for Cleveland.

Antawn Jamison led Washington with 23 points and 11 rebounds, while Caron Butler added 19 points. But it was Stevenson who was at the centre of the key play.