Just when you thought they had already crossed the galaxy of basketball possibilities, the Houston Cougars added something new to their razzle-dazzle-dunk routine tonight.

They made some free throws.

Consequently, Houston defeated Memphis State, 70-63, in an NCAA Midwest Regional semifinal game before a sellout of 17,036 at Kemper Arena. Houston entered the game shooting 61 percent from the foul line, but made 16 of 20 free throws tonight, including seven straight over the final 1:23 when Memphis State had closed to within a basket.

"I've been telling you guys all along," said Houston guard Reid Gettys, "when we needed to make the free throws, we'd get them."

So now, the Cougars (29-2) have won 24 straight games, longest winning streak in Division I, and will play Villanova here Sunday afternoon in the Regional final. The winner of that game will advance to the final four in Albuquerque, N.M.

Villanova earned the right to try to sever the Cougars' streak by defeating Iowa, 55-54, in the other Midwest semifinal earlier tonight.

"Houston can win it all," was Memphis State Coach Dana Kirk's postmortem. His Tigers were paced by forward Bobby Parks' 17 points tonight.

Akeem Abdul Olajuwon, Houston's 7-foot sophomore center, scored 21 points (10 of 14 shooting) and guard Michael Young scored 17. The Cougars held Keith Lee, Memphis State's 6-10 super-smooth forward, to just 13 points on six of 15 shooting.

"All week long in practice we were talking about Keith Lee," said Olajuwon. "It pumped me up to play harder. He is a very good player."

Houston did suffer through some worry tonight. Olajuwon and forward Larry Micheaux each scored six points in a 14-4 Houston streak that tore asunder 32 minutes of near-parity, giving Houston a 57-48 lead with eight minutes to play.

Then Memphis State (23-8), which eliminated Georgetown, 66-57, last week, rallied to within 65-63 with 40 seconds left. This came after the Tigers made several full-court-press-induced steals and baskets.

But Houston came to its senses. Guard Alvin Franklin made two free throws with 26 seconds left, boosting the lead to 67-63. After a Memphis State in-bounds violation, Young scored on a layup and the lead was 69-63 with 24 seconds left. And the game and the streak were saved.

The first game offered several portraits: first, it was a portrait of Villanova center John Pinone's finest qualities. The 6-foot-8, 230-pound senior scored 18 points (to scale the 2,000-point level in his career), had nine rebounds and made the two free throws with 12 seconds to play that guaranteed victory. A mammoth effort befitting of a guy called "Bear."

Furthermore, Villanova-Iowa was a portrait of equilibrium. With two minutes left, equality was located in nearly every game statistic, including the score. It was tied at 51.

That's when Iowa's senior guard Bob Hansen, who was so marvelous with 21 points worth of jumpers and drives, missed the front end of a one-and-one.

Villanova (24-7) rebounded and went into a spread offense, stalling until 23 seconds remained and sophomore guard Gary McLain was fouled by Hawkeye guard Steve Carfino, who tried to block his path. "If the call goes the other way," Iowa Coach Lute Olson said so solemnly, "the game could have been different."

McLain, an 81 percent free throw shooter, made both, even though Olson called two straight timeouts in between free throws in hopes of rattling McLain. Didn't work. So Villanova led, 53-51.

Iowa then rushed the ball inside to 6-10 sophomore center Greg Stokes, who scored 22 points and grabbed 11 rebounds in an effort of magnificence. Stokes missed the shot, but was fouled by forward Ed Pinckney. Stokes made just one of two free throws, closing Iowa within 53-52 with 14 seconds left. The miss hurt the Hawkeyes, but it was still a game.

Then Pinone was fouled in the back court. With 12 seconds left, came another brushstroke of clutch on the portrait of Pinone. An 84 percent free throw shooter, he made both for a 55-52 lead.

Hansen scored on a hurried eight-foot bank shot with five seconds left and the Wildcats' lead was just 55-54.

Villanova senior guard Stewart Granger, who scored 11 points, was fouled with three seconds left. When Granger missed both free throws, doom might have crashed down on Villanova's head. But Pinckney rebounded the second miss, keeping Iowa from getting a last shot.

And Olson, his Hawkeyes (21-10) eliminated, said, "Our old nemesis from the Big Ten regular season came back to haunt us: free-throw shooting."

The score was tied at 24 at halftime as Stokes' 10 points, earned off rebounded slam dunks and soft jumpers in the lane, almost matched the seven-point efforts of Pinone and Granger.

Michael Payne, Iowa's 6-11 sophomore who averages 11 points and nearly eight rebounds per game, fouled out with with 8:01 remaining. He produced just three points and two rebounds in 23 minutes. graphics/photo: Gary McLain and Stewart Granger gang up on Andre Banks of Iowa. AP