For 16 minutes last night, George Washington's basketball team played third-ranked Virginia evenly.

Then Virginia started to dominate defensively, the Colonials stopped making the 18-foot jump shots that had kept them in the game and, by the time the 80-54 rout was over, the capacity crowd of 5,000 at Smith Center had witnessed another night's good work by Virginia center Ralph Sampson.

As usual, the Cavaliers (17-1) were led by the 7-foot-4 all-America center, who finished with 18 points, seven rebounds and three blocked shots. Guard Othell Wilson made nine of 13 from the field to finish with 18 points, and Craig Robinson scored 13.

GW (9-5), whose four-game winning streak was broken, was led by Wilbert Skipper with 12 points. Freshman Mike Brown, who had scored in double figures in all 13 of the Colonials' previous games, had problems inside against Sampson and managed only nine points and six rebounds.

"He made me change my game," said Brown, who missed 11 of his 14 field-goal attempts. "It was a very good learning experience. I tried everything. I tried to go inside, then I went outside. Once I was five feet away from him and he still blocked my shot."

GW managed to stay close early by making 12 of its first 18 shots, none of them closer than 10 feet. Skipper and Oscar Wilmington had the best luck, scoring eight points each on medium-range jumpers over the Cavalier zone.

GW led by four points on three occasions before a base line jumper by Sampson tied the game, 12-12, with 14 minutes to play in the first half. Ten minutes later, the Colonials were still competitive, trailing, 28-26.

But the Colonials, who outrebounded the taller, more experienced visitors in the first 20 minutes (17-15), didn't make a layup in the first half and were unable to get Sampson in any foul trouble.

Wilson also did his part, scoring 12 first-half points, mostly on fast-break baskets against the slower Colonials. Virginia tightened defensively in the final five minutes before halftime and outscored GW, 11-2, for a 39-27 halftime lead.

"Defense is the name of the game," said Sampson. "GW was right there until we started to shut them down. Brown is going to be a good player. He hustled and has a nice touch."

But Brown and Penny Elliott (seven points) were unable to do what they do best: score down low. That meant the jump shots had to fall all night if the Colonials were to stay in this game. They didn't.

"As usual, we got another fine effort from Ralph and Othell," said Virginia Coach Terry Holland. "And our guys off the bench did a terrific job. Once we were able to get control by halftime, we were able to dictate what we wanted to do in the second half."

Sampson put a quick end to any ideas the Colonials harbored about making a game of this one. The junior started off with a dunk, scored on a turnaround jump shot in the lane and stuffed another shot to get his team rolling. Suddenly Virginia was off and running, 55-36, with 11 minutes to play.

"Instead of being down by eight or so, we're down by 16," said GW Coach Gerry Gimelstob. "Sampson got them off with that incredible dunk. Sampson isn't the only great player on that team. Wilson is a premier guard, (Jeff) Jones is good. They're a great team."

Once Wilson and Jones got the Cavaliers running, GW was virtually helpless. Virginia didn't get many second shots, mainly because it didn't need them. The Cavaliers made 34 of 58 from the floor, 12 of 15 free throws and had only 11 turnovers.

The only bright spot in the second half for the Colonials came when Wilmington, who is 6-3, blocked a layup by Sampson. Otherwise, the Cavalier reserves were having a ball.

"They aren't ranked No. 3 for nothing," said Skipper, who scored 23 points in last year's 30-point loss at Charlottesville. "They're good. They beat us on transition and played real good defense. But we don't plan to get our heads down over this loss. They've beaten a lot of good teams.