For the first time since 1972, Virginia has won its first two football games. Overcoming a school record-tying five interceptions, the Cavaliers defeated Navy tonight, 27-16.

Although the Midshipmen committed only one turnover, it proved more costly than all of Virginia's mistakes. On third and three from the Cavaliers' nine, with 5:21 to play and trailing, 21-16, quarterback Ricky Williamson fumbled the snap. Ricky Callinder recovered for Virginia and the Cavaliers promptly drove their way through the frustrated Midshipmen for 91 yards and an insurance score. Freshman tailback Beaver Petty of Annapolis, who outrushed the Navy team, got 65 of those 91 yards. His 22-yard sprint on first down seemed to take the heart out of the visitors.

Petty, redshirted a year ago because of mononucleosis, gained 128 yards in only 14 carries; Navy was limited to 96, 83 by tailback Napoleon McCallum.

When Virginia was able to defense McCallum, Williamson was forced to throw repeatedly. Although he completed 17 of 39 without an interception, Navy proved unable to fully exploit numerous scoring chances.

"It was ridiculous that we couldn't score more in the first half with four interceptions," said Coach Gary Tranquill.

It was even more ridiculous that Navy, after five times having the ball in Virginia territory and shutting out the Cavaliers for the first 28 minutes, went to its dressing room behind, 14-10.

Quarterback Wayne Schuchts' fourth interception led to a Navy touchdown on McCallum's one-yard dive with 3:26 left in the half. Virginia's defense, which earlier had stopped Navy on the one, was showing the effects of both the heat and its too frequent presence on the field.

On the first play following the kickoff, however, tailback Antonio Rice sprinted 47 yards around his right side on a fake reverse before he was caught from behind by linebacker Todd Hastings at Navy's 33. Four plays later, Petty swept left end for 15 yards and a touchdown.

Only 1:49 was on the clock when Petty scored, but Williamson's ill-advised short pass that fell incomplete on second down helped Virginia conserve the precious seconds and 42 seconds still were available after Bart Farinholt's 27-yard punt return gave Virginia the ball at Navy's 42.

Schuchts completed three of four to take Virginia into the end zone again, throwing to split end Billy Smith for the last 15 with six seconds left.

"Those two touchdowns were a big plus for us," said Coach George Welsh. "If we'd gone in 10-0, we'd have had big problems coming back. You have to give Schuchts credit, throwing so well after all his earlier problems."

Navy never regained the lead, but it had reason to believe it had early in the third quarter. Williamson spun left on an apparent keeper, then threw to tight end Mark Stevens on a play that covered 60 yards to the end zone. But an official back at the line of scrimmage ruled Williamson had crossed that line before throwing.

A 65-yard drive, which ended with Schuchts's two-yard pass to tight end Billy Griggs, increased Virginia's margin to 21-10 before the third period was over. Flanker Quentin Walker's 23-yard sprint off a double reverse began the drive and Petty's 17-yard sweep of left end on third down at the Navy 35 kept it rolling.

Williamson got hot in the fourth quarter and it was Navy's turn to roll in this roller-coaster contest. He completed three of six for 43 yards and was aided by a 16-yard interference call as the Midshipmen closed to five on a 12-yard pass to flanker Ken Heine with 8:26 remaining.

While Virginia's coaches vainly sought a timeout, the defense smothered McCallum as he took a flat pass on a two-point conversion try.

The ensuing kickoff got Virginia in deep trouble, as Malcolm Pittman expected it to go out of bounds and let it drop on the Cavaliers' two. He managed to reach the eight before he was tackled and Virginia was forced to punt, which enabled Navy to take over at the Cavaliers' 38.

A 20-yard pass to flanker Greg Brand helped take the Midshipmen to the nine, where Williamson mishandled the snap with 5:21 left.

Virginia stayed on the ground and wrapped it up, with Derek Jenkins covering the last 15 yards after Petty had made the principal contribution.

Schuchts' interception total matched the school record inflicted on Charlie Harding by Richmond in 1952. Virginia won that one anyway, 49-0.

"In football, try to expect anything and nobody will be disappointed," Welsh said.