Navy, 27 points ahead as the fourth quarter began, needed a fumble recovery by Steve Peters at its six-yard line in the final minute to escape with a 27-21 victory over previously undefeated Duke today.

The Blue Devils were limited to two first downs over the first 42 minutes and only once, in the last few seconds before halftime, were able to push beyond their 30.

But suddenly Duke again looked like a team with the nation's fifth-best offense. The Midshipmen, playing conservatively on both offense and defense, could not even put a dent in the clock as the Blue Devils became unstoppable.

Duke's first three possessions of the fourth quarter resulted in touchdown passes by quarterback Ben Bennett, as the hurry-up offense got scores on drives requiring only 1:19, 1:09 and 2:04.

The clock showed 2:40 remaining when Navy, stopped two yards short of a first down at its 30, was forced to punt, leaving Duke 68 yards from a miracle victory.

Bennett, sacked by middle guard George Herlong on first down, overcame it with a 20-yard pass to flanker Glenn Tillery. Five more completions, in six tries, brought the Blue Devils to a first down at the Navy 10.

Bennett, unable to spot a receiver, ran to his right and was about to go out of bounds at the six when defensive end Travis Wallington knocked the ball out of his hands. Peters fell on it, inches from the sideline, and Navy arms raised in victory.

"I saw the quarterback pump fake and I knew there wasn't anybody behind me, so I went for him," Wallington said. "He tried to tuck the ball away, but he couldn't get it down in time. I came down on him and knocked it loose from his arm."

Bennett finished with 32 completions in 50 attempts for 363 yards. Of that total, 259 yards came in the fourth quarter, when he had little pressure from a three-man rush and Navy was reluctant to blitz.

For the Midshipmen, sophomore tailback Napoleon McCallum gained 211 yards in 36 carries and quarterback Marco Pagnanelli completed 15 of 17 passes for 171 yards and two touchdowns. Pagnanelli's accuracy produced a Navy record, bettering Roger Staubach's 14 for 16 against Michigan in 1963.

Pagnanelli was perfect on 11 first-half passes, for 121 yards, but despite that success Navy Coach Gary Tranquill elected to stay on the ground with the big lead and almost paid a ghastly penalty. In the fourth quarter, Pagnanelli threw only once, to flanker Ken Heine for a nine-yard gain.

Navy's first two touchdowns followed interceptions by safety Kurt Dixon of Herndon, Va., the first two interceptions against Bennett this season. The first came at the Duke 47, after Peters put a big rush on Bennett, and the second at the Navy 45, with a return to the Duke 44, after Wallington jarred the passer.

McCallum scored the first touchdown, on a six-yard dash around left end, after Pagnanelli had made a skillful 26-yard run along the right sideline to make a big gainer out of a fractured flea flicker.

It became 14-0 when Pagnanelli, running with the ball near the line of scrimmage, suddenly stopped and threw a 40-yard scoring pass to Heine, eight yards behind the deepest Duke defender.

Steve Young kicked a 47-yard field goal to make it 17-0 at the half. It could have been much more, because Young was wide with a 22-yarder on fourth and one from the six, and Rich Clouse fumbled the ball away at the Duke 16 following a 55-yard run by McCallum.

Clouse lost the ball again at the Duke one in the third period, but it did not seem as if it would matter, because Young kicked a 43-yard field goal and Pagnanelli threw a nine-yard scoring pass to tight end Chris Weiler for a 27-0 advantage.

If ever a team could have quit, it was Duke. Many in the crowd of 32,750 were heading out the gates and some of those who remained were loudly booing the heroes of the past three weeks. When cornerback Eric Wallace picked off a Bennett pass on Duke's next possession, there were loud demands for second-string quarterback Ron Sally.

Coach Red Wilson stuck with Bennett, however, and he responded with six completions in seven throws on a 54-yard touchdown drive that culminated with a nine-yard pass to split end Chris Castor.

McCallum carried five straight times, for 14 yards, before Navy punted. It took Bennett only four plays, all pass completions, to move 80 yards for another score. It came on a 31-yard throw to freshman flanker Chuck Herring of West Springfield, who got behind Wallace in the end zone.

Navy managed two first downs before its next punt. This time Bennett moved the Blue Devils 63 yards to a third score, on a 24-yard pass to Tillery, who caught it between two Navy defenders.

On third and one at the Navy 29, McCallum was stopped by cornerback Harold Winstead. Navy punted and the Blue Devils prepared for one more march down the field. This time they came up short -- barely.

"We'd have been very, very down for the rest of the season if we'd lost this one," McCallum said.