DALLAS -- LeBron James drove for an emphatic dunk during a decisive fourth-quarter run and went skipping to the bench after a Dallas timeout.
The Miami star has sure had fun against his old nemesis this season.
James scored a season-high 42 points and the Heat tuned up for a showdown with Oklahoma City by beating the Mavericks 117-106 Tuesday night.
The 10-time All-Star was nearly impossible to stop in the first game after the break, topping his previous season high of 39 points in a win over Dallas in Miami in November.
This victory completed Miami's third straight season sweep of the Mavericks -- six consecutive wins -- since losing to them in the 2011 NBA Finals, James' first season after his celebrated signing with the Heat.
"He is great and we know he is great," Dallas coach Rick Carlisle said. "He scored a bundle of points on us last time and he was even better tonight."
James scored the first eight points and 10 overall in a 14-0 run that put the Heat up 106-95 after they trailed by one entering the fourth quarter.
Miami came out of the All-Star break by winning for the sixth time in seven games heading into James' duel with Kevin Durant on Thursday night in Oklahoma City. It's the last game of the Heat's second six-game road trip, a season high.
"I'm still tired," said James, who had 22 points in 33 minutes in Sunday's All-Star game. "But when I'm on the court, I've got to try to make things happen."
Dirk Nowitzki had 22 points to lead the Mavericks, who couldn't follow up a win at Indiana, the other top team in the Eastern Conference, in their final game before the break.
The deciding run started when James, who also had nine rebounds and six assists, stole a pass from Shawn Marion in the backcourt and pulled up for a tying 3-pointer.
After hitting another 3 over Marion to put Miami ahead for good, James drove for a dunk following Mario Chalmers' steal of a pass from Devin Harris. James made four of eight from long range after getting warmed up with a couple of dunks in the first quarter.
"When we turned it over, he was gone," Marion said. "After his fourth open-court dunk, the basket started feeling a little bit bigger for him. He just started taking pull-up 3s."
The Mavericks, who are in a tight battle with four teams for the final three playoff spots in the West, went without a field goal for 6 minutes after a four-point play by Vince Carter, who scored 15.
Dallas missed seven shots and had three turnovers while Miami pulled away.
"We played hard the whole night," Carlisle said. "We tried to keep it going and get some traction, but we had some untimely struggles. Let's put it that way."
Chris Bosh scored 22 for Miami and Dwyane Wade had 13 after missing the final two games before the break with a foot problem. Chris Andersen scored a season-high 18, including his second 3-pointer of the season for Miami's final points.
Chalmers had 10 points and nine assists for the Heat.
"When Bird is playing like that, we are so much more of a dynamic team," Wade said of Andersen. "When 'Bron is driving, he can see over the defence and he can find Bird for a lot of those lobs."
James scored 19 points in an entertaining first half that included an alley-oop dunk on a pass from near midcourt by Wade, a breakaway slam and the buzz of anticipation for another alley-oop that instead was a simple layup from Chalmers when Monta Ellis, the lone defender, chose to guard James.
Early on, the Mavericks looked primed for the only visit of the season from the two-time defending champions.
Nowitzki was on pace for a triple-double in the first half with nine points, seven rebounds and five assists, and Harris found Brandan Wright with a fancy pass for a running dunk that was thrown straight down, barely making a ripple in the net.
Nowitzki finished with nine rebounds and seven assists.
NOTES: Fans about 10 rows from the court were briefly distracted from the entertaining first half when two men were led out of the arena in handcuffs after an apparent fight early in the second quarter. ... The crowd included four of the Dallas Cowboys' biggest stars: QB Tony Romo, TE Jason Witten, WR Dez Bryant and RB DeMarco Murray.