The victory formula was brutish today, and not complex. The Washington Redskins defeated the Philadelphia Eagles, 23-13, before 69,542 boo-prone fans at Veterans Stadium, by putting the ball in the hands of running back John Riggins.

Riggins ran for 100 yards on 27 carries. Most importantly, he helped the Redskins untangle from an offensive stagnation that had left them gasping in the 98-degree heat, in a 10-10 tie, early in the fourth quarter.

"We just decided to go with our inside running game, our guts," said offensive guard Russ Grimm. "We went with the stuff that got us to the Super Bowl."

Meaning the Redskins (1-1) went with Riggins. He ran 14 yards for the touchdown that gave them a 17-10 lead with 13 minutes to play. He ran seven times--up the gut, across the gut, through the gut--in the subsequent 11-play drive that finished with Mark Moseley's 24-yard field goal--his third today--that gave the Redskins a 20-10 lead with 5:45 left.

"The Eagles played a great defensive game. They stuffed us in the first half," Coach Joe Gibbs said. "We made up our mind to run the ball in the second half."

In constructing a 7-3 halftime lead, the Redskins had gained just 33 yards on nine carries, so stingy was the Eagles' defense. That's when Gibbs decided to go into the playbook and storybook: the Redskins ran the ball on 23 of 36 second-half plays. Riggins ran the ball on 19 of the 23, gaining 71 yards and a lot of momentum.

"Riggins was getting hit every time. We weren't just tapping him either," said Eagles linebacker Jerry Robinson. Asked if life provides defenses with a way to stop Riggins, first-year Coach Marion Campbell replied, "With a cannon."

The Eagles closed to 20-13 when Tony Franklin barefooted a 33-yard field goal with 2:24 left in the game. Franklin had missed from 43 yards two minutes earlier, but got a reprieve when rookie cornerback Darrell Green ran into him, giving the Eagles a first down at the Washington 20.

Redskins free safety Mark Murphy then recovered the subsequent onsides kick at the Philadelphia 44. "I didn't even wait for it to go 10 yards," he said. "I went after it like my old baseball days, like I had a mitt." The Redskins got to a third and five at the Eagles' 39. As the defense awaited a pass, the Redskins did nothing of the sort: veteran running back Joe Washington ran 31 yards to the eight on a trap play.

"That was the game," said Robinson. "We felt like we were in it until then." With 19 seconds left, Moseley kicked a 23-yard field goal, perhaps for good measure and maybe for good riddance of the sad memory of his 31-yard fourth-quarter miss that could have helped the Redskins avoid that 31-30 loss to Dallas. It also put the finishing touches on the Redskins' eighth straight road victory, a team record.

Afterward, Riggins sat on a chair he placed on top of a locker room table. Wearing his favorite straw hat and suspenders over his bare chest, he said, "I said to (defensive coach) Richie Petitbon this week, 'Well, here's our first must-win.' You can talk about 15 more, 14 more to go, but that gets hollow real quick . . . (Today's game was) kind of like a heavywewight fight: carry 'em the early rounds with body punches, then dispose of them in the late rounds."

Riggins wasn't the only one inside the ring today. There were other contributing Redskins' heroes, like the defensive line that, using a little trickery by adding a rare 3-4 formation on second downs to the standard 4-3 front, sacked quarterback Ron Jaworski six times.

Redskins coaches said they used the 3-4 formation as a surprise strategy--"I was surprised," Jaworski admitted--as well as to rotate the defensive linemen on a hot day and allow them to avoid the fatigue that overcame them in the second half against Dallas.

Asked later if he had seen his open receivers through the arms of the charging defensive linemen, Jaworski, who completed 24 of 37 for 326 yards, said, "I wasn't watching. I had four gorillas chasing me."

Quickly remembering the furor raised last week when ABC's Howard Cosell referred to Redskins receiver Alvin Garrett as "that little monkey," Jaworski decided not to make a bad day worse. "Wait a minute," he said. "I better watch that. Make that 'four big guys' chasing me."

While Riggins was pounding out the glory, the defense dwarfed the Eagles' running game, holding it to 35 yards on 21 carries, a sickly 1.7 yards per carry average. Defensive tackle Dave Butz was the preeminent brick in the defensive wall.

Of course, the Eagles were without star back Wilbert Montgomery, who has a sprained knee. "Philadelphia just isn't the same without him," linebacker Rich Milot said. Rookie Michael Haddix, Montgomery's replacement, gained 17 yards in 11 carries.

There were other heroes, too, like kicker/punter Jeff Hayes, who had only one of his six kickoffs returned, for 19 yards, and reserve running back Nick Giquinto, the former Florida busboy who caught two crucial passes in the fourth quarter, for 21 yards and 20 yards. The first catch set up Riggins' 14-yard touchdown run, the second prolonged the drive that Moseley ended with the 24-yard field goal that made it 20-10.

The Redskins stole the tempo of this game early: poor Jaworski, playing without the aid of a running game or a pass-blocking offensive line, threw an interception on the game's first play. Murphy intercepted, sliding to his knees on the Eagles' 41.

Quarterback Joe Theismann, who completed 15 of 26 for 142 yards and one touchdown, then led the Redskins to their only productive drive of the first half. The drive finished with a 12-yard high-lob touchdown pass to wide receiver Charlie Brown, who beat cornerback Roynell Young in the right corner of the end zone. It was Brown's 10th touchdown reception in a career of only 11 regular-season games. It gave the Redskins a 7-0 lead with 10:32 left in the first quarter, and it gave cause to think the offense would produce with regularity.

It didn't. After their first drive, the Redskins got just one more first down in the first half. The Eagles' defense played coy and stingy.

Meanwhile, the Eagles produced lengthy drives (they outgained the Redskins, 156-74, in yards that half), but somehow managed to bungle them with inefficiency.

Franklin's 27-yard field goal in the second quarter allowed the Eagles to trail only 7-3 at halftime. The only factor clicking in the Eagles' clanking offense was 6-foot-8 wide receiver Harold Carmichael, who caught nine passes for 108 yards.

Prior to today, he had caught 79 passes for 1,148 yards and 10 touchdowns in 23 games against the Redskins. Today, he caught passes on a variety of curl and short slant plays, while being covered--chaperoned, really--by cornerbacks Vernon Dean, Green and Anthony Washington.

"But he didn't score any touchdowns," Murphy noted.

The Redskins' offensive woes continued early in the third quarter. Then Philadelphia constructed its only second-half drive that didn't seem as flawed and as the Liberty Bell. Seventy yards in eight plays, Jaworski took the Eagles. He finished with a 27-yard touchdown pass to wide receiver Mike Quick, who beat Green down the left side. That gave the Eagles a 10-7 lead with 8:25 left in the quarter. It was their only lead.

Riggins then carried six times for 20 yards on the ensuing 12-play, 51-yard scoring drive. Moseley kicked a 36-yard field goal with 3:26 left in the third quarter for a 10-10 tie.

The breakaway play came on the first play of the fourth quarter, when Philadelphia receiver Ron Smith, wide open, dropped a third-down pass that would have given the Eagles a first down at their 40.

Then Max Runager's 39-yard punt was returned 18 yards by Mike Nelms, who, bouncing around like a pinball, ran to the Philadlephia 43. Three plays later, the Redskins had third and two at the 35 and Theismann hit Giaquinto, who slid away from safety Wes Hopkins inside the 30 and ran to the 14. Riggins ran it in for the touchdown that made it 17-10.

The Redskins had four players injured: wide receiver Alvin Garrett(Bruised thigh), riggins (sprained ankle) and Dean (jammed neck). None are believed to be serious.

Veteran strong safety Curtis Jordan did not play because of a bruised thigh. He was replaced by first-year man Ken Coffey.