DALLAS — Dwyane Wade vowed to be healthy enough to play in Game 6. LeBron James insisted his team would be better. Erik Spoelstra sounded like someone already embracing an ultimate challenge.

Down, yes.

Beaten, no.

After seeing another chance to take control of the NBA finals slip away, all the Miami Heat could do was start prepping for a win-or-else game on their home floor Sunday night.

Wade played through a bruised hip to score 23 points, James had his seventh career postseason triple-double, Miami's oft-maligned bench scored 40 points, and it still wasn't enough as the Heat lost Game 5 to the Dallas Mavericks 112-103 on Thursday night.

Miami's first back-to-back losses in three months couldn't have come at a worse time: The Heat trail the best-of-seven series 3-2.

"White Hot," Wade tweeted early Friday morning in a message to fans, a nod to the Heat postseason marketing campaign. "See you Sunday."

They'll be there.

So will the Mavs, eager to turn the tables on Miami's six-game win in the 2006 finals.

A 17-4 Dallas run at the end was Miami's downfall, the third time in this series the Heat haven't been able to hold on to a fourth-quarter lead.

James finished with 17 points, 10 rebounds and 10 assists for the first triple-double in Heat playoff history, saying afterward his stat line couldn't have seemed less meaningful.

"The only thing that applies to me is a win. Win or a loss," James said. "I could have made a couple more plays for my team, but at the end of the day, all it is is about a win or a loss. And a triple-double means absolutely nothing, you know, in a loss."

According to the NBA and STATS LLC, James' was the 29th triple-double in finals history. But he was held to two points in the fourth quarter again, and those came with 29.6 seconds remaining. He had been stuck on 15 points for 15 minutes before his final basket of the game.

"I don't think it was a case of offense again tonight," said James, who was 8 for 19 from the field but was sent to the foul line for only two free throws, the fifth straight game where he's shot four or fewer — the first time that's happened in his career.

"There was enough offensive play. We shot 52 percent, they shot 56 percent. We scored 103 points, they scored 112. The offense wasn't a problem."

James has 11 points in the five fourth quarters of this series. By comparison, Mavs star Dirk Nowitzki has 52 in those periods.

"LeBron was much more aggressive tonight," said Spoelstra, the Heat coach. "Obviously, he had a triple-double. And he had an impact on the game."

There was a time when it seemed as if Wade would not.

Wade was hurt on a first-quarter drive, a collision with Brian Cardinal with 4:01 left in that period eventually forcing him to the locker room for treatment and evaluation.

Wade missed about 5 minutes of the first half, then remained in the locker room after halftime for additional treatment, not checking in again until 4:33 remained in the third quarter.

Wade was in obvious pain after the collision, grabbed at the outside of the hip repeatedly. Moments later, grimacing, he hobbled over to the Heat bench, fell to the court and covered his face with a towel while being tended to by Miami trainer Jay Sabol, then headed to the locker room.

He had 11 points at halftime and was Miami's best threat in the fourth, though his absence to begin the second half gave the Heat a scare.

"I said, 'I want to help us get back in this ballgame,'" Wade said. "And I was able to be effective, in a sense."

Mike Miller started the second half in Wade's place, making two 3-pointers for Miami's first two field goals of the third quarter.

"We as a team, we played good enough to win again," James said. "Put ourself in position to win down the stretch. Everyone, guys made plays. They just made a few more than we did. That's what it came down to."

It can't be that way on Sunday, or else his chase of a first ring will last at least another year.

"We'll be better in Game 6," James said.

His teammates — all of them — seemed to echo that way of thinking.

"We're going back home, so I think we've got all the momentum," said Heat guard Mario Chalmers, who scored 15 points off the bench. "Two games left and we're desperate."

Spoelstra showed his cards in his postgame news conference, laying out what he'll be telling the Heat until game time Sunday.

This team has gone through a whirlwind of issues all season, from the 9-8 start to the five-game slide in March and countless questions along the way about how a trio of stars such as Wade, James and Chris Bosh could play together.

He says that process has steeled the Heat. No better preparation than that before facing possibly two must-win games with an NBA title at stake.

"We're going home, and we wouldn't have it any other way than the hard way," Spoelstra said. "This is an opportunity for us. That's why you play a seven-game series. You've got to play it out. And this is where we feel comfortable."

Making sure Wade feels comfortable will be one of the many priorities Friday and Saturday.

He insisted the hip would be fine, though the Heat had concerns about how it may stiffen on the flight home to Miami and during whatever down time Wade has before the team returns to the court.

"I don't talk about injuries," Wade said. "It's unfortunate that I had to leave the game, but I came back and I finished it. ... Once you're on the court, you're on the court. I don't have no excuses. I was on the court. I was able to help my team get an opportunity to win and I'll be fine Sunday."

And, he hopes, Tuesday. That's when Game 7 would be played.

Follow Tim Reynolds on Twitter at http://www.twitter.com/ByTimReynolds