In past years, Mark Moseley would have kicked the 52-yard field goal and the game would have gone into overtime. But in this season of heartbreak for the Redskins, Moseley's kick tailed wide of the goal post by inches with 13 seconds remaining and Denver could celebrate a 20-17 triumph that will torment Washington for days to come.

It was the Redskins' fourth straight loss, but this one way by far the toughest, especially hard to take because of two successive penalties that wiped out good gains prior to Moseley's miss.

Washington had produced its best game yet, finally cranking up its running attack while bottling up Denver's offense for a good portion of the second half. Wilbur Jackson had romped for 104 yards, 55 on a touchdown run, and the team's short passing game constantly confused Denver's defense after intermission.

And when Joe Theismann connected with Art Monk on a one-yard pass with 7:30 left in the highly emotional contest, the rookie's first professional touchdown putting the Redskins ahead, 17-13, it appeared Washington was ready to break out of its slump.

But somehow veteran quaterback Craig Morton, who had replaced Matt Robinson in the second quarter, got himself untracked. Eluding a strong rush, Morton threw successfully into the heart of the league's top-ranked pass defense three times. His third pass wound up in the arms of Rick Upchurch, who took the 32-yard toss into the end zone just ahead of safety Mark Murphy for the go-ahead score with 3:08 remaining.

The Redskins couldn't believe it. On the sideline they started at each other, then dropped their heads. And their depression increased when Fred Steinfort's kickoff bounded by Jackson, possibly touching him before rolling out at the two. It appeared as if there were no final chances left.

But the officials ruled the ball had not hit Jackson. Denver kicked again and the Redskins took over at the 30 with 2:47 to go. This is when the heart-break really began.

An 18-yard pass to Monk, then an 11-yard strike to the elusive rookie, had Washington in Denver territory with two minutes remaining. Theismann found Harmon for seven more to the 32, but the play was nullified when tackle George Starke, playing for the first time in three weeks after injuring a knee, was called for holding.

It was the first holding call of the night on Washington, which had piled up 11 of those penalties the previous two games.

The Denver crowd started to celebrate, but Theismann wasn't finished. The Redskins called a dealy pattern for tight end Don Warren. As the Bronco defense charged after Theismann, he calmly dropped the ball to a wide-open Warren, also playing for the first time in nearly a month. Warren slammed through a gang of tacklers to the 28.

But wait. Another flag, this one on halfback Bobby Hammond for clipping 10 yards behind the play. Washington was pushed back 27 yards, to its 45. And the Redskins had no time out remaining. They had used two earlier when Theismann didn't like the calls sent in from the bench and their final one was taken away when Harmon reinjured his ankle on that negated seven yard gain.

The Redskins tried to cross to Denver by sending Hammond up the Middle. But he gained only three and the clock kept running.Now the only goal left was to get the ball close enough for Moseley to kick a field goal. A nine-yard pass to Harmon, playing despite that painful ankle, and a seven-yarder to Monk moved the Redskins to the Denver 35.

Moseley ran on. In the first quarter he had booted one from 23 yards, his first success in his last six kicks and only his third out of 11 tries this season. But maybe that chip shot had straightened him out.

He got into the ball well, sending it soaring toward the goal posts 52 yards away. But the ball started moving to the left, little by little. The official standing under the cross bar kept bending his body in that direction. Finally, he leaned far to the left as the ball slide barely by the left post. He signaled no good.

Moseley threw up his arms. His teammates either sank to their knees or shook their heads or stared blankly into the night. Someone patted Moseley on the rear but he walked away, to continue living this personal nightmare.

This was a night when the Redskins were convinced they could learn to start winning again. The team was almost completely healthy for the first time since training camp and, with Starke and Warren back in the lineup, the offense no longer would be plagued by inexperienced players making mistakes.

The optimism almost proved true.

After gaining more than 100 yards rushing in only one game this year, Washington powered for 184 in this one. Jackson, who had just 127 yards for the season, provided the spark with the 55-yard scoring romp that included a wonderful downfield fake around defender Bill Thompson.

With Theismann mixing in 18 completions on just 23 passes for 130 yards, the Redskins displayed the kind of attack that had been so successful at the end of the 1979 season. They moved the ball while refusing to allow Denver to run time consuming drives.

Not that Denver was ineffective when it had the ball. The Broncos quickly discovered that Washington still was vulnerable to the run and they pounded away at the gut of the defense for 165 yards. Although they weren't able to take full advantage of good field position during the mid part of the game, they still led all the way until Monk's touchdown.

An eight-yard run by Otis Armstrong, who had 107 yards in all, put the Broncos ahead, 7-0, in the first period. Moseley's field goal cut that lead to 7-3 but Steinfort's 57-yarder -- the third longest in league history -- 40 seconds before the half made the spread again seven.

Jackson, however, tied the score at 10 with his splendid run that began as a sweep around right end. He shook off one tackle at the line of scrimmage, then eluded Thompson before racing into the end zone. His teammates poured onto the field to congratulate him and the Redskin bench came alive.

Even when Steinfort connected from 23 yards in the third period, and even when Harmon fumbled at the Denver 10 early in the fourth, the Redskins didn't let down. They were ready when halfback Lawrence McCutcheon was hit at the seven by Murphy and linebacker Neal Olkewicz recovered at the five with nine minutes left.

Three plays later, Theismann lobbed a pass into the left corner of the end zone Monk got behind cornerback Steve Foley and hauled in the ball as Foley pushed him.He held on and Moseley's conversion gave Washington its 17-13 lead.

But Morton, who hadn't had much more success than Robinson, came through under pressure. His scoring pass to Upchurch was a thing of beauty.

"It was man to man coverage and I was playing him for a shallow crossing pattern," Murphy said. "But then he turned it up field, I just got too shallow."

Before Murphy could recover, the ball was in Upchurch's hands for the touchdown.

"It was our best game overall," said a dejected Murphy.

For now, that has to be the only consolation for the Redskins.