DALLAS - The Miami Heat didn't blow this one. Now it's just two wins from being crowned NBA champion.

Chris Bosh made a 16-foot, go-ahead jumper from the baseline with 39.6 seconds left and the Heat held on for an 88-86 victory over the Dallas Mavericks last night for a 2-1 lead in the NBA Finals.

Recent history says this is a huge win for the Heat. The Game 3 winner in a tied Finals has won the championship all 11 times since the 2-3-2 format began in 1985.

Miami got into this tight of a series by blowing a 15-point lead in the last quarter of Game 2. The Heat already had wasted a 14-point lead in this game when it went back ahead 81-75 with 6:31 left. Miami knew Dirk Nowitzki would drive Dallas' rally, but he burned the Heat anyway for 12 straight points - six free throws, a layup, a dunk and a tough jumper.

But after Bosh's clutch shot, Nowitzki's streak ran out. He tried passing out of a double team and threw the ball away, then hit the back iron on a jumper at the buzzer.

"This is a total win," said Dwyane Wade, who led Miami with 29 points and 11 rebounds. "You want to win the game on the defensive end of the floor and we got a stop."

The Heat goes into Game 4 tomorrow night with a chance to do what it did in 2006: win it all on Dallas' floor. Miami will need to win that game and the next, on Thursday night.

Bosh, a Dallas native who'd been 0-8 in his hometown, overcame a swollen left eyelid caused by a poke during the first quarter to scored 18 points. He had seven in the fourth quarter.

LeBron James added 17 points and nine assists. But he also had four turnovers, including a pair during the fourth quarter that helped bring Dallas back. Mario Chalmers added 12.

Udonis Haslem had only six points, but his tough defense on the final two possessions saved the Heat. When Nowitzki's final shot from the top of the key missed, Haslem swung his arms and screamed in delight.

Nowitzki finished with 34 points, but didn't get much help. Jason Terry scored 15 and Shawn Marion had 10, but both were shut out in the fourth quarter.

Wade was at his dynamic best from the start, looking like the guy who soared and scored the Heat past Dallas and to the title in 2006.

Most of his baskets came in the paint - where the Heat outscored the Mavs, 40-22 - and many of them were spectacular. But he also stemmed Dallas' rally by hitting a go-ahead jumper over Jason Kidd for Miami's second-to-last basket.

James came in talking about being more aggressive, but wasn't. He went more than 6 minutes before taking his first shot, but certainly made it worth the wait - a drive through the teeth of the defense for a powerful dunk. He also had a two-handed jam in the second half that put Miami up by 13.

The Heat just couldn't put the Mavs away. Dallas would surge close or ahead, then Miami would turn it up again. The final 18 minutes played out with both teams realizing any possession could change the game and the series.

Nothing came easy for anyone. Shots were contested, bodies collided for every rebound and guys were flying into the stands after loose balls. Fans stood throughout, wearing their blue gimme T-shirts and fired up by videos such as one featuring encouraging words from Roger Staubach, Troy Aikman, Emmitt Smith, Nolan Ryan and others.

Yet it was the visitors from Miami who walked off celebrating.