George Allen had not coached a game at RFK Stadium for more than five years, but he has changed no more than the color of the White House or the shape of the Washington Monument.

Minutes after he directed his Chicago Blitz to a 28-7 victory over the Washington Federals before 38,010 rain-soaked fans at the U.S. Football League's opening yesterday, Allen recited an ode to triumph familiar to a city that once followed his every exploit.

"Coming back here was a traumatic thing for me," he said. "Winning, whether it's in the NFL or the United States Football League or playing tiddlywinks, is it. I've said it before: When you win you are reborn and when you lose you die a little."

Some critics have accused Allen of spending too much too quickly to build his team, yet his results were indisputable. "We worked out in the mud and we worked out in the rain," he said. "We paid the price."

While the Federals' first-round draft choice, Craig James, could manage only 34 yards on 14 carries behind an erratic offensive line, Allen's two top picks proved instantly valuable. Wide receiver Trumaine Johnson of Grambling caught 11 passes for 158 yards and one touchdown and running back Tim Spencer of Ohio State carried 17 times for 69 yards.

No one would confuse the quality of play in the new spring league with the theatrics of last January's NFL playoffs. However, Greg Landry, Allen's graying, 36-year-old quarterback, said, "It felt like early September in the NFL to me. Of course, there isn't parity, but I like to think there are a few NFL teams we could compete with. At the skill positions we're getting there. The difference is in the offensive and defensive lines."

Landry, who played 14 years in the NFL with the Detroit Lions and Baltimore Colts, provided the experience the Blitz required, completing 17 of 27 passes for 251 yards and two touchdowns.

On defense, led by former Lions linebacker Stan White, Chicago enacted a simple strategy.

"Our No. 1 objective was to stop Craig James," Allen said.

The Blitz scored their first touchdown with 4:25 remaining in the first quarter. Working from Washington's 33, Landry passed to Johnson on an out pattern. After catching the ball, Johnson cut inside and headed for the goal line. As he was tackled at the two the ball squirted into the end zone. But wide receiver Wamon Buggs recovered and the extra point made it 7-0.

Landry set up the next touchdown with passes to Johnson and Kevin Long. With 8:10 left in the half, Long scored on a four-yard off-tackle run and the score was 14-0.

Kim McQuilken, who once backed up Joe Theismann for the Redskins, started the game at quarterback for the Federals. But under a persistent rush he could complete only two of seven passes and fumbled twice.

"They beat us in the trenches," said General Manager Dick Myers. "We had trouble getting it going in the first half."

After Chicago's second score, Mike Hohensee replaced McQuilken. The former Minnesota quarterback showed promise, completing 16 of 28 passes for 178 yards, mostly in the second half.

Coach Ray Jauch said afterward he wasn't sure if Hohensee would start against the Los Angeles Express next week. "We'll hash it all out tomorrow," he said. "Right now, I just don't know."

The Blitz completed their domination of the first half with a two-minute drill. Starting from his 12, Landry passed to Johnson and Lenny Willis to move Chicago to Washington's 23.

On the next play, Landry threw to Johnson, who made a leaping catch between Donnie Harris and Gregg Butler with 18 seconds left and it was 21-0.

After a scoreless third quarter, Landry completed a 10-yard scoring pass to tight end Paul Ricker with 7:34 left in the game to end a 10-play, 61-yard drive.

As the crowd began to thin out, Hohensee tried in vain to bring the Federals close, if not to victory. His efforts ended the way the game would end: in frustration.

On one fourth-quarter drive, Hohensee passed his way to the Blitz 22; on another he got to the 20. But each time safety Luther Bradley intercepted a pass in the end zone intended for Reggie Smith.

Washington's touchdown, on Hohensee's 19-yard pass to Walker Lee, a former assistant golf pro at Hilton Head, S.C., came with eight seconds left.

"There's not much to say," said Hohensee. "We've got to get in better shape. We've been kind of lax in our conditioning."

"The fans were great," said Lee. "I just hope they don't give up on us."

Said James, "We've got to want it a whole lot more than we seemed to want it today. They (the Blitz) always had great field position and we never did. They could afford to just let loose on defense. We held back."

As the players headed for the exit gates and the rain fell ever harder, David Dixon stood in the bowels of RFK Stadium wearing the grin of a proud father.

Dixon is a New Orleans art dealer and the founder of the USFL, and he wore a gold medal to commemorate the league's opening day.

"I'm an emotional person ever since I was a little boy," he said. "As I watched today, I wept. I looked at three of my sons and they were weeping, too. I looked up at my wife and she was blowing kisses. God, I've been waiting for this day for years and here it is."