On a day when Calvin Hill's legs carried the offense and two tipped passes helped produce a pair of first-quarter touchdowns, the Washington Redskins escaped RFK Stadium with a tense 17-14 victory over the Los Angeles Rams yesterday.

Because Ram kicker Rafael Septien missed a 40-yard field goal, after getting a reprieve on a running-into-the-kicker penalty, as time ran out, the Redskins finished the 1977 regular season with a 9-5 record. They went home to await their playoff fate.

A loss by either the Minnesota Vikings last night against Detroit, or Chicago today against the New York Giants, would advance the Redskins into the playoffs.

Hill, starting in place of injured Mike Thomas, has his most productive day since he joined the Redskins in 1976, gaining 89 yards rushing, 27 more through the air and helping to set up both Redskin touchdowns.

Riding touchdown catches of 59 yards by Frank Grant - the longest Redskin play of the season - a three-yard touchdown reception by tight end Jean Fugett and Mark Moseley's 45-yard field goal, the Reskins opened a 17-0 lead going into the fourth quarter.

But the Rams rallied for two fourth-quarter touchdowns, produced mostly by a second-team backfield. Rookie quarterback Vince Ferragamo also managed to move his team into range for a last-second field-goal try that would have produced the Redskins' first overtime game of the season.

Ferragamo replaced starter pat Haden with 2:09 left in the third period, surely a sign that Ram coach Chuck Knor was in no mood to risk Haden in a meaningless game for the Rams. Running back Lawrence McCutcheon sat out the entire second half.

But Ferragamo was not about to concede anything. He directed Los Angeles on touchdown drives of 72 and 62 yards. Then with time running out, he faked out all of America, including the Redskin defense, by calling for a Cullen Bryant sweep instead of a pass to set up September's game-tying attempt.

The call came on fourth and six from the Ram 49, and there were only 18 second left when the play began. The Rams wer esaving one time-out to get Septien onto the field.

Ferragamo, calling the play himself, handed the ball off to reserve running back Brynant, and he chugged around right end for 24 yards before Chris Hanburger dragged him down at the Washington 27.

Yeah, he called that play himself," said Knox. "It was an obvious passing situation. It was a heck of a play."

With six seconds remaining, Septien's 45-yard field-goal attempt saield wide to the right. But as scores of jubilant Redskin fans poured out onto the field, the Rams were jumping for joy because of a running-into-the-kicker call against Washington's Joe Harris.

"He made one of the greatest fakes I've ever seen," Harris said. "I didn't hit him, he came into me and took a dive. He even admitted it. I said to him 'I didn't hit you.' He says, 'Well, I'm not the official' and he's got this big smile on his face."

But not for long.

The five-yard penalty didn't help Septien. His second kick, from 40 yards, was wide to the left.

The Redskins won mostly because of two tipped passes and three quarters of solid play by a defense that forced Haden to miss his first nine passes. At the half, the Rams were nothing for seven on third-down conversions, and were struggling.

The Redskins opened a 7-0 lead late in the first period on a Billy Kilmer pass that should have been intercepted by Monte Jackson. Intended for tight end Jean Fugett, the ball bounced off Jackson's fingers and into the grateful arms of Grant.

Grant caught the ball at the 25, and trotted into the end zone. "I just saw six hands go up," Grant said. "The ball was tipped and heading my way, so I just reached down and grabbed it. I figured I'd just go to the end zone and see what happens."

The next big tip came four minutes later, when Dave Butz got his meaty paw on a Haden pass and safety Jake Scott intercepted. His five-yard return gave the Redskins the ball at the Ram 33, and they did not squander the opportunity.

Hill gained six yards on a sweep, four more on a dump-off pass over the middle, then caught a Kilmer pass at the right sideline in full stride before going out of bounds at the three.

From there, Kilmer faked a hand-off into the line, as Fugett angled toward the right corner of the end zone. Fugett was alone when he caught Kilmer's pass, and Moseley's extra point gave the Redskins a 14-0 lead with 38 seconds left in the first period.

"It was just a play-action pass," said Fugett. "In that kind of situation most teams are looking for the run. The guy who was supposed to cover me came right by me to cover a sweep. I didn't make any kind of great move. I just went to where I was supposed to go, and the ball was right there.

"I tell you this, watching Calvin today gave me a real feeling of dejavu.It was like the old days in Dallas. I'd make a block, look up and there was Calvin roaring right by me. "We're all very happy for him. He's still got a few yards left in him."

But the Rams also had a few more yards left in them after Haden left the game. haden seemed more intent in bombing the Redskins to death with a half-dozen long incomplete throws. Ferragamo was more content to take the short stuff, and hand off to running backs Bryant, Wendell Tyler and Rod Phillips.

Ferragamo finished with eight completions in 14 attempts, with touchdown passes of 17 yards to tight end Terry Nelson and two yards to Jim Jodat.

Still, the Rams were able to produce only 14 points against a Redskin defense that has given up only 189 points this season, the best-ever showing under Allen and the lowest Redskin point total since 1945 when NFL teams played only 10 games each.

The most productive tackling terror yesterday was linebacker Hanburger, who had seven solo hits and three quarterback sacks, all on Haden. The Hams' second-year completions in 20 attempts for 63 yards.

And so, when it was over, the Redskins all headed for home, or as Diron Talbert said "to church. It's a shame you have to pray against somebody," he said, "but that's how life body," he said, "but that's how life is."

"I'm just proud we still have a shot, that's all I can say. We worked so hard for 20 weeks to get it. I'm proud of this team. It's been a dog fight every week. But it's been a heck of a year, no matter what happens."