DALLAS - A chance for another championship ahead of him, Dwyane Wade refused to look back.

No, he said, the answer as quick and forceful as his first step to the basket. He doesn't consider that the Miami Heat should have a 3-0 lead in the NBA finals.

The margin is 2-1, close on the scoreboard even though it doesn't feel that way on the floor. The Heat have repeatedly built double-digit cushions against the Dallas Mavericks, and a late collapse in Game 2 is all that's keeping them from the lead that's never been blown in an NBA series.

"You can't think about stuff like that. Everything in life happens for a reason," Wade said Monday before practicing. "If we come in and we win that game, if we run away with that game, I don't know if our sense of urgency is the same in Game 3. Who knows? So our sense of urgency was that way for a reason. We lost the game we know we shouldn't. We are up 2-1. That's what we have to focus on and worry about."

The Heat insist the game isn't as easy as Wade and LeBron James are making it look, and the Mavericks refuse to admit they might just be facing a superior foe.

"We're just too stubborn," point guard Jason Kidd said Monday.

Game 4 is Tuesday night, and a Heat victory would put them in

position to win a second championship on the Mavericks' floor if they followed that with another one Thursday.

Wade clutched the finals MVP trophy that night five years ago, already a superstar in just his third NBA season, and figured he would be back plenty of times. Instead, the Heat never truly contended again - partially because they were clearing salary cap space for last summer - until James and Bosh agreed to join him in Miami.

With that trio together, the Heat could win multiple titles, but Wade doesn't want to wait.

"Nothing is promised to none of us," he said. "You never know what's going to happen in this game. If you get your opportunity, you have to seize it."

That's why he and the Heat could be disappointed about where the series stands. They led by 12 in Game 1, were up 15 with 7:14 to go in Game 2, and they had a series of double-digit advantages in Game 3, when it peaked at 14 points. Forcing turnovers on defense that sent Wade and James off for fast-break dunks, it's often appeared they could run away from the Mavericks whenever they wanted.

Yet Dallas rallied to pull out Game 2 by two points and kept coming back Sunday before falling 88-86. And though they've been playing from behind, the Mavericks remain unconvinced that's where they'll end up.

"I still feel like we're going to be NBA champs this year," center Tyson Chandler said. "It's a hard fight. Nobody said it's going to be easy. I've got the ultimate respect for those guys on the other side.

"It's going to be a tough road, but I feel like we're willing to do it."

The finals have had consecutive games decided by two or fewer points for the first time since 1998, according to research provided to the NBA by the Elias Sports Bureau. So even when his team is building those sizable gaps, Heat coach Erik Spoelstra doesn't expect them to last, adding that regret over not having the 3-0 lead is "wasted energy."

"It's a possession series," Spoelstra said. "So many different things could happen during the course of the game. Make here, a miss here, a rebound here, a loose ball there, that can change the complexion of it."

So can Wade and James. Both are so good they can carry the Heat when the other is struggling. When both are rolling, it might be too much for Dallas' defense to stop.

"Those guys cause problems, and what we've got to do is we've got to approach it, we've got to guard each of those two great players with really all five of our guys," Dallas coach Rick Carlisle said.

Kidd had to face the Lakers of Shaquille O'Neal and Kobe Bryant in his first finals trip, when his New Jersey Nets were swept by the Lakers in 2002. As good as the Heat's duo is, Kidd said it's not the same helpless feeling for the Mavs.

"This a different scenario, different team," Kidd said. "We were just happy to be there. In this sense, we're not. We feel we can compete with Miami. We wouldn't have been here if we didn't think that."

But the Mavs will have trouble beating them without more help for Dirk Nowitzki. Already a team without a certified No. 2 option, Dallas has looked even weaker in its losses, when James defended top reserve Jason Terry in the fourth quarter and held him without a basket in either.

Nowitzki said the Mavs have to free Terry and their other perimeter shooters for better looks so they "don't chase them down 15 all night long, which takes a lot of energy out of everybody."

And eventually, the Heat won't blow one of those leads, so the Mavs know they can't keep playing from behind.

"It's very frustrating, because you feel like you have to climb out of a hole we shouldn't have," forward Shawn Marion said. "At the same time, because we have to work that much harder to get out of them holes, we're draining so much energy. We've got to play from a lead, and we need to make sure when we do get the lead that we sustain it."