On a night when Boston College had all the right answers on how to stop Ralph Sampson, along came Lee Raker to provide Virginia with the crucial points in a 57-55 Cavalier triumph in a second-round game of the 43rd National Invitation Tournament.

The victory moves Virginia, the Atlantic Coast Conference's only entry in the 32-team tournament, into Thursday's quarterfinal round. The Cavaliers will play Michigan here.

Raker, who has bounced back from a midseason shoulder separation suffered against Old Dominion, scored a team-high 17 points tonight, including the Cavaliers' final five points after Boston College had crept to within one, 52-51, with 42 seconds to play.

Boston's Vin Caraher, the Eagles' leading scorer with 24 points, had a chance to tie the game at 52, but missed the second half of a one-and-one free throw situation and Terry Gates rebounded for Virginia.

Moments later, Raker was fouled and made one free throw. After John Bagley missed B.C.'s last opportunity at a tie, Raker was back on the foul line to make two free throws and give Virginia a 55-51 lead. The 6-foot-6 junior shots for a 57-53 lead with six seconds left.

Although Virginia (21-10) led through the second half, Boston College (15-10), which claimed among its victims Georgetown and is coached by Tom Davis, a leading candidate to replace Bill Foster at Duke, didn't make it easy for the Cavaliers.

Playing a sagging defense against the 7-4 Sampson, the Eagle guards rarely ventured outside of the foul line on defense, challenging Jeff Lamp and Raker to shoot from outside.

The defense worked.

In a sloppy, deliberate first half, the Eagles remained close, with Virginia holding a 24-22 lead with two minutes to play. Then Raker got hot. v

Raker scored Virginia's five final points for a 29-23 halftime lead. Lamp had 11 but Sampson had been kept to four points.

With Sampson and Lamp hitting baskets to open the second half, Virginia took its biggest lead, 33-23, before Boston began its comeback.

Eight straight B.C. points narrowed the gap to 33-31. Virginia held a 41-39 lead midway through the half before Raker tossed in two jumpers for a 45-39 lead.

But the Cavaliers couldn't put Boston away as Sampson got into foul trouble and eventually fouled out.

Sampson finished with a game-high 14 rebounds but managed only 10 points, making five of them from the field. He was the only Cavalier to foul out, but three Eagles were whistled off by the three-man Mid-American officials crew.