MIAMI — Only a few minutes after the Miami Heat’s winning streak reached 19 games, Erik Spoelstra laid down the next challenge.

And it wasn’t to win a 20th straight game.

Instead, it was to simply win tonight.

Dwyane Wade scored 23 points and on a night when the stat sheet would suggest a struggle, the Heat rolled once again, extending their winning streak and leading wire-to-wire in beating the Atlanta Hawks 98-81 on Tuesday.

Next up: The Heat are in Philadelphia at 6 p.m. tonight.

“It’s a privilege for us to get in our cars and hop on a plane and get into Philly at 4 a.m. after this win and do this again tomorrow night,” Spoelstra said. “That’s the way we’re going to approach it. No excuses.”

For about six weeks now, no excuses have been needed — not even on nights where things went far from perfectly for the reigning NBA champions.

The Heat shot only 43 percent and LeBron James was just 3 for 11 from the field, with the field-goal total matching his lowest from any regular-season game in more than three years.

And they won by 17.

“Let’s be honest, guys,” said James, who scored 15 points. “We’re not sitting here and saying this is not something special. This is an unbelievable streak that we’re on. We’re playing great basketball. We’re winning in different phases of the game, we’re playing different styles, we’ve won every game, on the road, at home, double-overtime games, end-of-regulation games, whatever the case may be.”

Chris Bosh and Mario Chalmers added 14 apiece for the Heat, who matched the fifth-longest streak in NBA history.

Only three teams have won at least 20 consecutive games in the same season: the 1971-72 Los Angeles Lakers (33), the 2007-08 Houston Rockets (22) and the 1970-71 Milwaukee Bucks (20). The Washington Capitols also won 20 straight, spanning the end of the 1947-48 season and the start of the 1948-49 campaign.

“Ten is enough for me,” Bosh said. “Twenty’s cool. I’d take it.”

Josh Smith scored 15 for the Hawks, who got 12 apiece from Al Horford and Jeff Teague.

“Miami is playing very well right now. You have to give credit where credit is due,” Hawks coach Larry Drew said. “Coach (Erik) Spoelstra and his staff over there are doing a great job. Their team is really moving the basketball, they are playing together, they are playing at a very, very high level right now, and they’re really good right now. We just got beat by a really good basketball team.”

Ray Allen scored 12 and Udonis Haslem grabbed 11 rebounds for the Heat. The crowd was 20,350, a record at AmericanAirlines Arena.

Miami now leads San Antonio by 1 1/2 games in the race for the NBA’s best record and is atop the Eastern Conference by 9 1/2 games over Indiana and New York, who were both idle Tuesday. The Heat (48-14) have 20 games left, while the Pacers have 19 and the Knicks 21.

It was the first game in which the Heat went without trailing since Feb. 14, when they won at Oklahoma City in a surprisingly one-sided NBA Finals rematch. They’ve needed buzzer-beaters and double-overtimes and big rallies to win several times since, often against opponents who won’t be headed to the playoffs, teams like Orlando and Cleveland and Sacramento.

The Hawks are headed to the postseason — barring a most improbable collapse, anyway — but this one was never in doubt.

Seven Miami players logged more than 3 1/2 minutes of time in the first quarter, all seven of them scored, and the snowball started rolling. James was falling down near the 3-point line on one possession, yet still had the sense to just tap the ball to Wade for a layup that gave Miami an early 17-8 lead. And later, after Haslem missed inside, he got the rebound and fed Allen for a step-back corner 3-pointer that swished.

Yes, it’s going that well for Miami right now.

“Leading with our defense has been the key for us,” Wade said. “When we come out defensive minded from the beginning of the game, it gets us into the game, it gets us on the offensive end, we’re moving the ball. We have been playing well offensively all year, but defense is the key.”

The Hawks closed to 41-40 midway through the second quarter, the third — and last — time they were within a point. Miami needed just over two minutes to score the next 10 points, the run both starting and ending with 3-pointers from Chalmers, and the margin was 51-40.

As if the Heat needed any more help late in the first half, the often-enigmatic Smith gave them a little boost.

For no apparent reason, Smith fouled Bosh with 0.1 seconds left until intermission — doing so about 80 feet from the Heat basket. Miami was in the bonus, so Bosh took two free throws, made both, and the Heat went into the break with a 57-44 lead.

An hour later, they were packing for Philadelphia and a chance to win No. 20.

NOTES: James was called for goaltending after blocking a shot by Ivan Johnson late in the third quarter. James didn’t like the call, and if that wasn’t enough, he swatted the ball into the leg of Bosh’s wife, Adrienne, who was seated courtside. She was fine. … The Hawks lost Teague with 3:08 left in the third quarter after he turned his left ankle. He returned to the bench later in the period after getting re-taped, but did not return to the game. … Heat assistant coach David Fizdale shared a warm embrace with Drew a few moments before the game. Fizdale is a former Atlanta assistant.