HOUSTON — The Knicks were more “Superbad’’ than “Superteam’’ in a dreary preseason opener.

New point guard Derrick Rose referred to the Knicks as a “superteam’’ in the offseason, and he showed bursts of brilliance driving to the basket for buckets in scoring 16 points (7-for-14) with five assists in his club debut on his 28th birthday.

But the Knicks were a disaster on defense and started out dreadful offensively — going 5-for-25 in the first quarter — and were blown out by Mike D’Antoni’s Rockets, 130-103, behind James Harden’s sensational 28-point, 11-assist masterpiece.

“I’m more worried about our defense than anything,’’ Rose said. “We’re going to score the ball. We have to become the team defensively when you come in, you’re going to have a hard time on that side of the ball. We want to be known for our defense when we come into the regular season.’’

The Knicks were missing defensive center Joakim Noah (hamstring strain), and that may have affected the defensive dynamic. Rose and Carmelo Anthony said new coach Jeff Hornacek also didn’t give detailed defensive instructions.

“It’s the first preseason game,” Hornacek said. “No need to panic. They are a tough team to play as your first game.’’

The Knicks’ offensive star was Kristaps Porzingis, who got hot in the second half and racked up 22 points in 28 minutes, making 8 of 11 shots, 5 of 6 from beyond the 3-point arc. Anthony put forth a clunker, playing too much isolation ball and wound up with 10 points, shooting 4 of 13.

“We didn’t really have nothing to go off — a game plan,’’ Anthony said. “We need to protect the paint. It’s a weird team to play against without no scouting report. We know they want to shoot 40 3s and that’s not something we’ve worked on.’’

The Rockets found it as easy to score on the Knicks as they did the Shanghai Sharks. In the Rockets’ preseason opener Sunday, they racked up a 134-94 rout of Shanghai. The Knicks left Rockets shooters open from the 3-point line and were slow in switching on pick-and-rolls. Hornacek had said the Rockets would “really test our defense,” and he was spot on.

Houston’s Ryan Anderson dropped in 7 of 13 3-pointers.

“I want to see more physical play on the ball,’’ Hornacek said. “We were playing it too safe.

“We need to work on our weakside help and we gave up too many open looks on 3s.”

After a poor-shooting first quarter, the Knicks’ defense became sieve-like in the second period. They fell behind 68-42 at halftime — inept on both sides of the ball.

“We still got a lot of time and it’s just one preseason game,” Rose said.

Harden got his 28 points on just 11 shots. He made 4 of 8 3-pointers and 10 of 12 free throws. Late in the second quarter, the Knicks looked to be standing around watching as athletic K.J. McDaniels soared to ram down two alley-oop dunks to put the Rockets in front by 24 points. D’Antoni’s club sank 8 of 22 3-point shots in the first half.

“We have to get better defensively,” Porzingis said. “We have to talk more.”

In the first quarter, Anthony got off to a lousy start, shooting 1 of 4 with two offensive fouls, holding the ball too much on offense. The Knicks got penetration from their two point guards — Rose and backup Brandon Jennings — but didn’t finish well. In fact, the attacking Jennings was 1-for-7, getting blocked twice near the rim.

Rose didn’t seem distracted by his civil trial for alleged sexual assault, which began earlier in the day in Los Angeles.

“I hope I looked 100 percent,’’ said Rose, who scored his first points as a Knick on a mid-range pull-up jumper, then added a driving reverse layup and a crossover dribble move for a floater.