Georgetown gave much of the nation a glimpse of the future yesterday.

With 10,823 watching at Capital Centre and much of the rest of the country watching on television, the Hoyas outscored Nevada-Las Vegas, 20-2, midway through the second half and went on to stun the Runnin' Rebels, 76-52.

Georgetown (7-2) never trailed, led by three at the half, then ran the Runnin' Rebels off the East Coast in the second half. The surge, which began with 13:05 left and the Hoyas leading, 46-39, ended with eight minutes left and the score 66-41.

"We just fell apart completely," said UNLV Coach Jerry Tarkanian. "We stood around and fell to pieces. It blows my mind."

That was understandable. UNLV is a quick, talented team. Yesterday, Georgetown made it look pathetic. The catalyst was Eric (Sleepy) Floyd, who did everything but help Billy Packer with his TV analysis. Floyd had 27 points on 10-of-17 shooting from the floor, including several jumpers that seemed to come from McDonough Arena.

More important, he, Fred Brown and Patrick Ewing were the keys in the Hoyas' pressure defense that turned this into a rout in the second half.

"People talk so much about Eric's shooting that sometimes they forget what a good defensive player he is," Coach John Thompson said. "He does a lot of things for us that aren't shooting."

The Georgetown run came so swiftly that UNLV (4-3) was left standing wondering what had happened. The Rebels had trailed, 36-33, at the half after a sloppy, rough first 20 minutes. The Hoyas had led by as many as 12, shooting 61 percent from the floor, but could not hold that margin, partly because of their 13 turnovers and partly because Ewing had to sit down with three fouls with 8:04 left. His absence opened up the middle for the Rebels. With Ewing in the game, UNLV rarely even tried the inside and from outside it was awful, shooting 41 percent each half.

But it was still a game, 46-39, thanks mainly to Sidney Green, who scored all 14 of his team-high points in the first 23 minutes. Then the defense began clicking.

Mike Hancock started it off a feed from Brown, then Floyd made a shot, throwing a layup past four players while being knocked to the floor. He made the free throw for a 51-39 lead.

Michael Johnson finally got two points for UNLV. Brown, Anthony Jones (six of nine in his best all-around game of the year) and Floyd -- on a dunk off a steal by Hancock -- made it 57-41. Another UNLV turnover, another Floyd long-distance shot. Tarkanian tried a timeout.

No use.

Brown stole the ball and Ewing dunked. Floyd stole and dunked, stole again and fed Jones. After Richie Adams grabbed the rim in frustration following that basket, Floyd made the free throw. It was 66-41 and Tarkanian had his head in his hands.

"It was the defense, no question," Floyd said.

"We're more aggressive with it now than we were," added Eric Smith. "Guys are going to the right places and there's a lot more arm movement, waving arms. We're cutting off the passing lanes with that."

The Hoyas also cut the Rebels off by showing them the first man-to-man defense they had seen since their opener.

In the second half, the Hoyas dropped their zone and, playing man to man, Ewing showed flashes of the kind of dominant force he is expected to become. His statistics were good: 10 points, eight rebounds, four blocks. But perhaps more important, whenever UNLV tried to go inside something went wrong -- an off-balance shot, a fumbled pass or, 28 times, a turnover.

Ewing, after the third foul, did not commit another and, happily for Thompson, concentrated strictly on basketball the second half. He had three impressive dunks, started the game with a sweeping hook and made a soft base-line jumper. He was, in short, very good.

He was not alone. Brown, after a horrendous start, played his best game in two weeks with 11 points, five assists and eight of the team's 14 steals.

"He stunk the joint out early," Thompson said. "Then he played like hell."

They all played that way, especially the wondrous Floyd. When it was over, Floyd was telling the hordes about how good he thought UNLV was. If so, someone asked, how good are you guys?

Floyd smiled. "I don't know yet."

Neither does anybody else. But they are beginning to find out.