When things are going right, blitzes become sacks, last-second plays become game-winning touchdowns and the season ends in a Super Bowl victory.

When things are going wrong, blitzes backfire, desperation plays are stopped short of the goal line and virtual playoff elimination comes before Dec. 1.

For the defending Super Bowl champion New York Giants, every week is becoming a new corollary for Murphy's Law.

In yesterday's 23-19 Redskins victory at RFK Stadium, Ricky Sanders scored the deciding points as Giants cornerback Perry Williams slipped on the wet grass and left Sanders all alone for a 28-yard touchdown with 4:56 remaining in the game.

The Giants started a final drive with 56 seconds left and no timeouts. On the game's last play, running back Tony Galbreath took a dump-off pass 14 yards, but was stopped by Dennis Woodberry on Washington's 2.

"Our game plan was good," said Giants secondary coach Len Fontes. "We just seem to be self-destructing; you don't put it in the game plan for a guy to fall down. We had two men blitzing on their last touchdown and {Jay} Schroeder had to throw it quick. But the one thing you fear on the blitz is, if somebody falls down, there is no one else back there to help but God, and I think he was in Indianapolis today."

Williams, whom Fontes said has been his most reliable defensive back this season, refused to comment after the game. Mark Collins, New York's left cornerback, said a steady rain made the footing bad throughout the game, although it played a significant factor on only that one play.

"The footing here normally is not very good to start with, and when it got wet, it was even worse," said Collins. "Perry just slipped; it could have happened to anybody."

Fontes maintained that the defense did an overall good job despite giving up 23 second-half points.

"I tell my young cornerbacks that if there are 70 plays in the game and you do well on 67 of them, in this league, it still means they will get three touchdowns on you," he said. "We hadn't any adversity in the secondary for the past three weeks. Today, {Schroeder} beat us on the outside three times and it meant 20 points."

The Giants, who rushed for 96 yards in the first half, saw their offense stall as Joe Morris found the previously open holes between the tackles closed in the second half. He was held to 17 net yards on 13 second-half carries, but in the final minute, quarterback Phil Simms seemed like he might have one more miracle drive left over from 1986.

Starting at the New York 21, he threw passes of seven and 21 yards to Galbreath and 35 yards to wide receiver Lionel Manuel for a first down at the Washington 16. He intentionally threw an incomplete pass into the ground to stop the clock with four seconds left, and hoped to find either Manuel or Stephen Baker in the end zone with his final pass.

"I looked downfield first and then I looked at the defense," said Simms, who completed only 12 of 29 passes, but said he felt no ill effects from the knee injury that sidelined him the past three games. "I didn't know if anyone was behind me, but I couldn't take the chance. I saw the people ahead of Tony, but I thought if he could break a tackle or slip by one, he had a chance."