John McDaniel's stunning, leaping catch of a 25-yard touchdown pass from Joe Theismann with 1:24 left to play vaulted Washington to a 21-19 victory over the inspired Detroit Lions yesterday in a fierce affair the Redskins nearly lost.

The Redskins came into the Silverdome yesterday smug and sassy after Monday's win over Dallas. They left here undefeated in six games but slightly humbled, even if they are off to the team's fastest start since the 1940 squad won its first seven games.

"Our players weren't at their highest psychologically today, but they had enough poise to win and I like to see that in a team," said Coach Jack Pardee. "We needed a couple of lucky breaks there, and we got them. Sometimes you have to have a little luck. I'm sure not complaining."

The Redskins managed only two first downs in the first half, but they stayed in the game on the strength of second-year man Donnie Harris' block of a punt and Gerard Williams' ensuing end zone recovery for a touchdown with 66 seconds left in the half.

And even though Theismann was flogging himself for "not playing a very good game," he still hit tight end Jean Fugett with a perfectly thrown 21-yard touchdown pass early in the fourth period.

When the Redskins had to march 74 yards with only 2:33 left in the game, there was Theismann hitting his last three passes of the day, including the game-winning touchdown pass to McDaniel on a pattern that was originally designed to pick up a quick first down at the sideline and stop the clock.

The Redskins maintained their two-game lead over the Dallas Cowboys in the race for the NFC East divisional title. With less than two minutes to play, however, it hardly seemed possible.

The Lions had moved out to a 19-14 lead on the strength of Benny Ricardo's four field goals and a six-yard touchdown run by Rick Kane with 5:52 left in the game.

Then the Redskins faced third and four at their own 32-yard line with 1:56 to play. Theismann dropped back and found Mike Thomas open over the middle for a 13-yard gain to the Redskin 45.

The Redskins were trying to pick up a few yards and kill the clock on a sideline pass to Thomas. "But when I caught the ball (at the right sideline), I looked around and nobody was on me," Thomas said. "So I just stayed with the sideline and got what I could."

Aided by McDaniel's timely screening block that kept two Lions from getting to Thomas and nudging him out of bounds, the little running back didn't stop until he had gained 30 yards to the Lion 25.

With 1:31 left to play. Theismann dropped back again. McDaniel was split out on left side when Lion cornerback Tony Sumler, a rookie acquired by Detroit earlier in the week, came up to the line in an attempt to jam the receiver.

"The play was originally supposed to be an out pattern for me," said McDaniel, a free agent claimed by the Redskins the first week of the season. "But when the guy (Sumler) came up on me to bump and run, I'm supposed to take it deep. So that's what I did.

"The man came up and I got right by him. Joe made a great throw. They also tell me Fugett was open down the middle. The (defensive) back recovered and was right on me. I don't know if he bumped me or if he hit the ball.

"All I do is concentrate on the football. If he hits me, they'll call it, so I know I'm going to have a chance to catch the football. It's all a matter of concentration. No question, that was my biggest catch."

Theismann never saw it. He was flat on his back after a wicked - and illegal - late hit by Lion defensive end Bubba Baker. The penalty was assessed on the Redskin kickoff, and Mark Moseley's boot from midfield sailed out of the end zone.

The Lions took over at their own 20 with 1:24 left in the game and managed to push the ball to the Redskin 45 with 30 seconds left. On second and four from there, linebacker Brad Dusek came blitzing in and sacked Lion quarterback Gary Danielson for a 10-yard loss.

On third down, a pass intended for Kane was nearly intercepted by Williams. And on Detroit's fourth-down play, Danielson took off upfield, was hit by Dusek and deliberately fumbled the ball forward, as Ken Stabler of the Oakland Raiders did earlier this year to beat San Diego. Officials ruled he threw an illegal forward pass and the Redskins took over from the Lion 47 with six seconds left.

Theismann took the snap and collapsed in a heap as the final gun sounded.And later, he admitted, "I feel I regressed, I didn't read my keys well, I wasn't disciplined enough. But give all these other guys credit. And you can't say enough about that blocked punt, either."

No you can't.

The Redskins were trailing, 9-0, late in the first half when their punt return unit trotted onto the field with 1:15 left in the period. "All we thought about," said Harris, "was block that kick."

Pardee said he thought Lion punter Tom Skladany was "holding the ball a little long and he was really getting into his kicks earlier in the first half. We decided to go for the block so at least we cold make him kick it quicker and not get all the hang time and distance."

Harris, who spent last season on the Redskin injured reserve list, lined up over the Lion left tackle, got off quickly on the snap of the ball and was on Skladany in a flash.

"We had worked on the play all week in practice," Harris said. "As soon as I saw the center's hand move, I went. I was hanging in the air so long it almost scared me. But I got all of it. Hit me right in the chest. But it feels real good."

It felt even better when Williams leaped high to pick up the bouncing ball deep in the end zone, fighting off several teammates, including McDaniel.

"I was just trying to get the ball before it went out of the end zone," Williams said. "We didn't need any safety, we needed six. We were all coming to the block. If Donnie didn't get it, somebody else would have."

The Lions did manage to add another field goal for a 12-7 lead with 4:18 left in the third period. But the Redskins marched back in answer and took the lead for the first time on the second play of the fourth quarter.

Fugett made a leaping catch deep in the end zone of another perfect Theismann pitch. "I didn't know if they had a blitz on or whether they were so sure it was going to be a run they just didn't pick me up," Fuett said.

"It wasn't any kind of great move or anything. The linebacker (Paul Neumoff) tried to recover but he couldn't get there. Actually, that was about the best thing I did all day. I didn't block well at all, and I'll take the blame for the running game not going. I'm just happy I could contributed something."

The Lions came back midway through the fourth period when they marched 62 yards to Kane's six-yard touchdown - the first allowed by the Redskins in 12 quarters - for a 19-14 lead.

The Lions were marching all over the field most of the day, gaining 374 yards, 231 on the ground against a Redskin defense that put up two stirring goal-line stands to force shortrange Ricardo field goals.

The Lions controlled the football for 38 minutes, ran off seven more first downs and had the ball for 77 plays, compared to the Redskins' 53. They also held Washington's offense to 76 yards rushing and intercepted two of Theismann's passes.

"We could have played better," said middle linebacker Harold McLinton, "but give those guys a lot of credit, too. They came in here loose, and they came in her proud. They wanted to win this game and they knocked us around. But we came back and that's what you have to like about this team."

Over on the other side of the locker room, Fugett agreed.

"That's not a 1-5 team we just played," he said. "Here we just beat the world champions on national television and you would think we're supposed to come in and watch them roll over and play dead.But somebody forgot to give them the message.

"But I've also been on a lot of winning teams, and these are the kind of games you have to win. You have to win when you don't play well, and we did.

"I think we finally had a chance to prove how good we are: that's what we kept saying to each other in the huddle on that last drive. I know it's easy to say this now, but we all believed we could win it, that we would win it. We didn't know how, but we never gave up.

"In the long run, this game is going to be good for us. It'll teach us you can't take anybody lightly. I'm just glad to get out of here alive."

Lamar Parrish started and finished the game despite a sore back that kept him out of practice the last week. "I tried it in the warmup and decided to go with it," he said. "There are days you just have to take a little pain, and this was one of them. Parrish had a decent day, knocking down a half-dozen passes, including three in the end zone . . . The Redskins suffered their usual assorted bumps and bruises, but had no serious injuries.