The Los Angeles Rams rolled up 21 points in the fourth quarter yesterday and continued unbeaten with a 34-17 victory over the Minnesota Vikings at Metropolitan Stadium.

The Rams' 7-0 record kept these four games ahead of Atlanta and New Orleans, both 3-4 in the NFC West. Minnesota, now 3-4, is tied with Tampa Bay, which also lost yesterday for third place in the NFC Central.

Tommy Kramer replaced starting quarterback Fran Tarkenton for Minnesota with 3 minutes 35 seconds remaining, but Kramer was injured with 2.38 to go. He was carried from the field on a stretcher with an apparent neck injury.

Haden used the clock well near the end of the half and put the Rams ahead the first time, 13-10 on Frank Corral's 40-yard field goal with two seconds remaining.

Haden took the Rams 30 yards in 62 seconds on a 14-yard pass to running back Cullen Bryant and five- and 11-yard throws to wide receiver Ron Jessie to set up the three-pointer.

The Vikings scored first, on a five-yard pass from Fran Tarkenton to wide receiver Sammy White in the first quarter.

It came after cornerback Nate Wright intercepted Haden's pass and ran 30 yards to the Los Angeles seven-yard line.

The Vikings had another scoring opportunity in the same period when running back Lawrence McCutcheon fumbled and linebacker Fred McNeill recovered on the Los Angeles 27. But defensive tackle Larry Brooks sacked Tarkenton for a loss of eight yards, and the quarterback then missed White in the end zone.

The Rams went 67 yards, mostly on a 16-yard pass to tight end Terry Nelson, a 13-yard run by McCutcheon, and a 34-yard pass to running back John Cappelletti, before Corral kicked a 31-yard field goal on the first play of the second quarter.

The Viking answered that with a 38-yard field goal by Rick Danmeier. Fifteen-yard passes to tight end Bob Tucker and Ahmad Rashad ate up most of the yardage.

The Rams tied the score at 10-10 on a 54-yard push featured by a 17-yard pass by Haden to tight end Nelson and 20 to wide receiver Willie Miller. Bryant ran six yards for the touchdown. Then came Corral's second field goal.

The rain resumed at the beginning of the third quarter.

The Vikings regained the lead in the third period of Tarkenton's 29-yard touchdown pass to White. Line-backer Matt Blair set it up, intercepting Haden and running 20 yards to Los Angeles' 25.

Tucker lost four yards on a screen-pass reception before Tarkenton went to White at the goal line. Danmeier's conversion made it 17-13, Vikings.

Running back Chuck Foreman was ejected in the third period for jostling an official.

The Rams took the lead on a three-yard scoring pass from Haden to McCutcheon in the fourth quarter.

Jackie Wallace, a former Viking, ran back Mike Wood's 35-yard punt 20 yards to the Minnesota 32.

McCutcheon and Cappelletti moved the ball to the three-yard line on rums and then Haden fooled the Viking defense with his touchdown pass to McCutcheon. Corral's conversion put the Rams ahead, 20-17, with four seconds gone in the final quarter.

The Rams boosted their advantage to 27-17 with 9:05 to go when line-backer Isiah Robertson recovered Mark Kellar's fumble and ran 16 yards for a touchdown. Corral converted.

Tarkenton dropped back to pass on the play but was under great pressure and ran toward his own goal line. He unloaded a desperate pass to Kellar, which would have lost 14 yards had he held on to it. But he fumbled it and Robertson caught the ball in the air and took off for the score. Kellar could have saved the play by intentionally dropping the ball for an incompletion.

It was the first time in 10 years that the Rams won here.