The Philadelphia Eagles, appearing to let up after they found out their closest challenger in the NFC East had lost; increased their division lead to two games today with Ron Jaworski's first career 300-yard passing game carrying them to a 34-21 victory over New Orleans Saints.

But the Saints twice threatened to ruin a perfect winless season before Jaworski's third touchdown pass to Harold Carmichael this afternoon clinched the Eagles' ninth victory in 10 games. The Eagles now lead Dallas by two games in the NFC East after the Cowboys' 38-35 loss to the New York Giants, a game that was ending just as this one began in the Superdome. y

Even with the best record in the NFL, accomplished with star running back Wilbert Montgomery nursing an injury much of the season, the Eagles are not yet talking about how they will return here for the Super Bowl Jan. 25, at least not until they play the all-of-a-sudden hapless 3-7 Redskins Sunday in Washington. The Eagles have subsequent games against Oakland, San Diego and Dallas.

"You know what they say about the NFL," said Carmichael, who enjoyed his first three-touchdown day ever. "On any given Sunday. . . "

Even against the Redskins?

"Yes, the Saints or Redskins," Carmichael replied. "I'm not talking about any return trips to New Orleans until after we visit the Redskins next week. Maybe not even then. We can't afford to move to a bigger hat size the rest of this season. There are six games remaining."

Carmichael, his streak now at 122 for consecutive games with a pass reception, scored his first touchdown today on a 10-yard pass from Jaworski with less than two minutes gone in the second quarter to bring the Eagles to a 7-7 tie.

The Saints' offense, which played brilliantly until quarterback Archie Manning hurt his passing hand late in the third quarter, scored on its first possession to take a 7-0 lead. Manning, who completed 25 of 40 passes and three touchdowns, threw the first of two touchdown passes to tight end Brooks Williams, playing in place of injured Henry Childs.

After a Manning 17-yard touchdown, pass to Wes Chandler made it 14-7, the Eagles brought the Saints back to earht.

"We were expecting a good game from them," said Eagle linebaker Reggie Wilkes, "but it started getting a little close."

However, Tony Franklin kicked a 32-yard field goal with three minutes left in the first half and Jaworski threw his second touchdown pass to Carmichael, this one a six-yarder. They hooked up once more on a 25-yard touchdown, one play after Louie Giamonna (montgomery's replacement) burst up the middle for 44 yards to begin the second half. That gave Philadelphia a 24-14 lead.

The Saints got the crowd pumped up one more time with an eight-yard touchdown pass from Manning to Williams, making it 24-21. After the Eagles failed to make a first down following the kickoff, the Saints drove from their six to the Philadelphia 31. But successive third-down penalties on tackle Stan Brock thwarted the rally. Then Franklin's 30-yard field goal and Mike Hogan's three-yard scoring run secured the Eagles' sixth straight win.

"We knew Dallas was behind before we took the field," said Wilkes. "The Cowboys are, of course, our closest competitors. They'll be the team we'll have to beat the rest of the season. We really expected Washington to give us our biggest challenge this season, but they've had a lot of adversity.

"With all the contractual disputes, players walking out of camp early and "some key injuries," Wilkes continued, "they seem to have their minds on too many things besides football. But next week's game in Washington will be tough. The players on both teams are really familiar with each other. It'll be like a cross-town rivalry."

Said Carmichael: "I've gone a long time without having a really good game against the Redskins. We've got a tough week of practice ahead."