Cassell’s Offensive Surge Leaves Knicks Breathless : Game 3: Rookie guard’s three-pointer and late free throws power Rockets to 93-89 victory and 2-1 edge in series.

Sam Cassell was on the ground and in obvious pain after getting the wind knocked out of him early in the fourth quarter Sunday night, so much that it prompted the Houston Rockets to call a 20-second timeout. But he declined to come out of the game, if only momentarily to catch his breath, instead staying in to retaliate.

He knocked the wind out of the New York Knicks.

The team that hadn’t played well in the fourth quarter in the first two outings of the NBA finals and the rookie point guard who mostly played in the fourth quarter this season provided a strange coupling at Madison Square Garden. They held steady in the face of another impending disaster and he took it from there, making the go-ahead three-point basket and then sinking four consecutive free throws in the final 22 seconds to give the Rockets a 93-89 victory in Game 3 and a 2-1 series edge.

“It was a big character win for us,” Coach Rudy Tomjanovich said.

On a couple of fronts, foremost, for the Rockets as a whole.

Coming off back-to-back disastrous fourth quarters at home, one which they survived and the other that did them in, they entered Madison Square Garden, shooting a combined seven of 37 in those 24 minutes. Then, Sunday, they had a stretch of 11 consecutive misses and five turnovers that reached back to the end of the third period. The offense consisted of four free throws, and two of those were from illegal defense calls.

Fittingly, Cassell broke the drought with a driving layup with 7:18 left, pushing a Rocket lead that was 14 in the fourth quarter back to four, 75-71. It was a nice warm-up to his personal character test, this 24-year-old from Florida State who had more turnovers than assists the first two games (seven to six) while going four of 12 from the field.

That cushion held up until Patrick Ewing’s 18-footer from the left side with 2:52 remaining put the Knicks ahead, 82-81. The Rockets regained the lead, then New York went up again, finally at 88-86 on a basket by Derek Harper with 53 seconds to go. Welcome to Houston’s gut check.

The Rockets, of course, answered by getting the ball inside to Hakeem Olajuwon. But when the defense collapsed around him, part of the Knick tactic that limited the regular-season MVP to 21 points on eight-of-20 shooting, Olajuwon whipped the ball from the left post to Cassell, standing just beyond the three-point arc and straight out from the basket.

“I was making my move,” Olajuwon said, “but I saw an opening. And it was wide open. I’d rather take a three than a two. That’s a chance I wanted to take.”

Cassell went up as Harper started to run at him with a raised arm. The shot got off, then went through with 32.6 seconds left to put the Rockets up, 89-88.

“Dream (Olajuwon) created it all,” said Cassell, whose 15 points were one more than all of the New York reserves. “He had three guys on him. He made the pass. I made the shot.”

The Knicks called a timeout. When Charles Oakley couldn’t find someone to take the inbounds pass, they called another. Oakley got the ball to Harper on the next try, but disaster struck: Ewing, setting a pick a few feet from the basket on the left side in hopes of springing John Starks free for a jumper or pass inside, got called for a moving screen by official Jake O’Donnell. Offensive foul.

“You can’t make a call like that, especially at that point in the game,” Ewing said.

Said O’Donnell, one of the league’s most respected referees: “It was a judgment call. The play was a pick and roll. He moved his hip out (immediately before) and then he did it again. I’m not gonna let it be twice.”

The Knicks were now forced to foul to stop the clock. Harper did the honors when he grabbed Cassell with 22 seconds left. Cassell made them both. Starks made one free throw with 3.9 left for New York and purposely missed the second in hopes of an offensive rebound and tying basket. No luck. Otis Thorpe got the loose ball for the Rockets and called a timeout.

When Cassell took the entry pass, he was intentionally fouled with 2.4 seconds left. He made both again, providing the 93-89 margin and another chapter in an unusual season, when he went from No. 24 pick in the draft to taking over Scott Brooks’ role as the fourth-quarter replacement for starter Kenny Smith as Tomjanovich continues to platoon his point guards.

“It’s taking a chance, it’s a gamble,” the coach said of his unusual rotation. “If it doesn’t turn out right, morale suffers.”

There’s no concern about that today. Everything turned out just right.

* GOOD FOR THE PRESS: No one is enjoying the Knicks’ wild ride through the playoffs more than the New York tabloids. C4