The Buffalo Bills took a big step toward their ultimate goal Saturday.

They also may have paid a big price.Scoring touchdowns on their first two possessions after giving up a quick early touchdown, the Bills beat the New York Giants 17-13 to run their record to 12-2, the NFL's second best and move to within a game of clinching home-field advantage for the AFC playoffs.

But they also lost quarterback Jim Kelly, who directed those drives, with a sprained knee of still undetermined severity and are likely to be without him for their showdown next week with Miami that probably will decide the AFC East title. Neither coach Marv Levy nor the doctors would say how severe the injury was, but Kelly said he expected to be out three or four week - "unless I'm lucky."

"I just hope he's back. We need him," strong safety Leonard Smith said of Kelly, hit by his own left tackle, Will Wolford, who fell into him when he was pushed by onrushing New York linebacker Carl Banks. Kelly, who completed 7 of 11 passes for 115 yards, was replaced by Frank Reich, whose main contribution was a 43-yard pass to Don Beebe that set up Scott Norwood's 29-yard field goal on the first play of the fourth quarter.

"We've proven in the past we can rally around Frank Reich," said center Kent Hull, noting that Reich was 3-0 last season when Kelly separated a shoulder. "The offense will do what it has to do and the defense showed that it can pick it up when it has to."

Giants quarterback Phil Simms also was knocked out of the game, suffering a sprained arch in his right foot in the third quarter, and there is some question whether he will be ready for Phoenix next Sunday.

"Right now, we're calling it a sprained right foot," Dr. Russell Warren, the Giants team physican said. "It looks significant. It's a sprain of the mid-foot."

Warren did not elaborate on his "significant comment. He said Simms would have a tomograph Sunday, an X-ray that shows an organ or tissue at a particular depth.

"I really can't say anything," Simms said before getting in his car. "They taped it at halftime. I just tried to throw and it went. I'll have to wait and see."

Simms' replacement, Jeff Hostetler, drove his team into scoring position four times but had only one Matt Bahr field goal to show for it and that came after Darryl Talley stuffed Ottis Anderson for a loss on a third and one at the Buffalo 3.

The other drives were stalled by a holding penalty, a botched snap in the shotgun and an offensive pass interference. Lawrence Taylor also dropped what looked like a sure interception for a touchdown on the play before Kelly was hurt as the Giants lost for the third time in four games. They are now 11-3, have clinched the NFC East, but need to win their last two games at Phoenix and New England to avoid a possible first-round playoff game.

"We had about 10 opportunities to make something happen," said coach Bill Parcells of the Giants, who outgained the Bills 313-266 and controlled the ball for 38 minutes to 22 for Buffalo.

"Each time we did something that didn't allow us to win. We just did some very untimely things. Two penalties, the bad snap, two dropped interceptions."

"I had the opportunities to make the difference," said Taylor, who later dropped another potential interception. "I just couldn't make the plays. There's no way we should have lost the game, especially after Kelly went down."

But as Hull put it, Buffalo did what it had to.

After a 41-yard run by Rodney Hampton, who carried 21 times for 105 yards, set up Anderson's 1-yard TD run at the end of a 71-yard drive with the opening kickoff, Kelly put up two quick touchdowns.

On Buffalo's second play, Kelly hit Thurman Thomas in the flat and the Bills' elusive running back broke three tackles and took the ball 48 yards to the New York 26. Kelly completed that drive with a 6-yard TD pass to Andre Reed just 1:28 after the Giants' score.

"That was a big turnaround, being able to score right away after they came down and scored," Levy said.

They came back again to make it 14-7 on Thomas' 2-yard run 51 seconds into the second quarter. Again there was one big play to set it up - a 36-yard pass from Kelly to Reed.

Bahr's 23-yard field goal cut it to 14-10 at halftime and then began the battle of the backups.

Hostetler and Reich were about equally effective, each throwing for 97 yards - Hostetler on 9 completions in 16 attempts; Reich on 8 of 15. Hostetler also scrambled 5 times for 23 yards.

But Reich made the one big play, the pass to Beebe. He also was good enough last season in those three wins - 23-20 over the Rams; 34-3 over the Jets and 31-17 over the Dolphins, next week's opponent.

"What I did last year gave me more confidence when I got out there today," said Reich, who was 6 of 13 for 50 yards this season before Saturday but has only those three starts in his six-year career.

"Hopefully I can keep it going."