Sonny Jurgensen remembers the boo-birds of Philadelphia.

"It was the second game of my career, 1957, and I'm an Eagle rookie starting against the Redskins," he says. "I go out and throw three touchdown passes and we win. Going off the field you had to walk through a side of the stadium to get to the locker room and I swear to you, the people are booing and throwing beer cans at me. All I'm thinking to myself is Geeez, what do I have to do around here. Where did I go wrong?'"

Tommy McDonald, the classy little reciever who was Jurgensen's teammate and target in Philadelphia, remembers, too.

It did't matter who was playing, or what you'd done for 'em the week before. If you loused up, you'd hear it from 'em. But I gotta say this, too. There is no more loyal fan in all sports than the Philly fan. If it's close to Christmas he may boo Santa Claus. But he'll never abandon ship. They'll always come back the next week. They'll boo ya, but they'll love ya, too."

And now, finally, after years of losers, Philadelphia's sports teams are paying back their loyal followers with victory upon victory. The Eagles beat the hated Cowboys last Sunday to win the National Football Conference title and will play Oakland Jan. 25 in their first Super Bowl. The Phillies last fall won their first World Series. The 76ers advanced to the NBA finals in 1979-80 and have the league's best record right now. The Flyers won the Stanley Cup in 1974 and 1975, reached the finals last season and should be there again this year.

Is it any wonder they are starting to call this town "The City of Champions," even if it may be a bit premature?

"Why not?" asks Eagle General Manager Jim Murray, who suffered through the bad times and the dreadful teams. "I have a hard time putting what this means into words. The people have been long suffering but they always stuck with us. They had great charity for us, and now there's a great warmth coming out of this town. You go anywhere in the city, and people are happy today.

I always like to say that we were two touchdown underdogs to the British, and the only reason anybody has a franchise today is 'cause we beat the odds then. So, now, maybe we're being paid back for it. We spent so much time in the rain, for the sun to come out now is just beautiful."

From the Main Line manisions to the tenements in South Philly, the town is awash in Eagle green. The signs, mass produced by the peppery tabloid Philadelphia Daily News, are everywhere -- in apartment windows, storefronts, newsstands, subway stations. "Fly Eagles," they read. "Next stop, Super Bowl."

"What would happen if we beat the Raiders?" asks Murray. "Well, I'd like to think it won't read like a bad Mexican earthquake -- you know, 10 dead, 500 trampled. I just hope it will be with enthusiasm, not insanity."

Still, you can hardly blame Philadlphians for getting excited. After all, consider what they've endured in the 20 years since the Eagles last won the NFL championship in 1960.

The Phillies of 1961, for example, lost 23 straight games, a modern record. The 1964 Phils botches a 10-game lead in the last two weeks of the season and blew the pennant.

How about the 76ers? Could anyone ever forget the 9-73 team in 1973, the worst in NBA history?

Even the Flyers suffered. Their first year, the roof blew off their building, The Spectrum, and in their fouth season, a Buffalo goal in the final four seconds of the last regular-season game kept the team from the playoffs.

Still, the Flyers changed the city's loser's legacy with their Stanley Cup championships. Was it any wonder that 2 million people lined the streets to honor the Flyers after their Cup victory over Boston in the spring of 1974?

Some people are saying now that the Flyers' success led indirectly to the resurgence of the Eagles, Phillies and 76ers. "I think that first Stanley Cup was the catalyst for winning teams in Philadelphia," Ed Snider, the Flyers' owner, says in the current issue of Inside Sports. "It changed the whole atmosphere."

"I'm not so sure about that," says Pat Williams, the general manager of the 76ers. "I just think the ownership of all the teams in town have made commitments to excellence. They've hired the people to run the teams, they've spent the money to get the players and they've given the fans what they want to see. Why all of a sudden is everyone winning? It's hard work, good decisions and a lot of breaks and good luck.

"The fans have a lot to be pleased about. They've got very little to boo any more. The fans here have had the reputation for booing a cure for cancer. aThat's changing now. they're becoming known more for enthusiasm, insanity. Did you see all those kids taking off their shirts during the Eagle game? All the masks, the crazy outfits. I think it's wonderful."

And so, too, does Chuck Bednarik, the hard-nosed, two way terror of the Eagles' last championshp team. He remembers the boos, too, but he also recalls 10,000 people meeting the Eagles at the airport when they clinched the Eastern Division championship in 1960. Now, he says, there is a similar hysteria in the streets.

It's the same kind of reaction," said Bednarik, now a sales representative for a frozen food firm. He also helps Coach Dick Vermeil as an unofficial assistant coach on game days. "All I hear everywhere I go is Eagles, Eagles Eagles. And when I travel, people are recognizing the city for more than just fans who boo. They're not saying we've got the worst teams in the world with the worst fans in the world. They talk about our players -- Pete Rose, Dr. J, Ron Jaworski, Bill Bergey."

And the players are talking about the fans, as well.

In the locker room following the Ealges' NFC victory over the Cowboys, Bergey was beside himself with joy.

"I don't just want to go to New Orleans to be there," he said. "I want to go there and bring back that trophy. I want to do it for the people in this city, in the Delaware Valley, for all the support they've given us, especially during the bad times.This is a city of winners, and these people have been coming out and screaming for us for years. We owe it to them. We love them."

In Philadelphia, the feeling is mutual.