The Baltimore Colts nudged the Buffalo Bills from their eminence, as the only unbeaten team in the National Football League today and left the Bills complaining about the officiating after a 17-12 loss in cold, rainy weather.

The Colts exploited two poor punts by Greg Cater in the first quarter for a touchdown and a field goal and added the rest of their points before the first half ended when a "confused" call by umpire Pat Harder set up another Baltimore touchdown.

On that play, Bert Jones of the Colts attempted to pass from the Buffalo eight-yard line to wide receiver Roger Carr. Free safety Bill Simpson intercepted. But it was ruled that a Buffalo defender made illegal contact with Carr five yards beyond the line of scrimmage.

The Bills were penalized half the distance to the goal line and, on third down from the Buffalo one, running back Don McCauley plunged for a touchdown.

In an explanation after the game, referee Jim Tunney was quoted as saying, "There was confusion about whether it was No. 57 (linebacker Lucius Sanford), but it is now believed it was 57 who tripped Carr, constituting illegal contact. The ball was not yet in the air, so it was not pass interference."

Some Buffalo players reported that Harder first said it was cornerback Mario Clark who tripped Carr, then said it was Sanford, but that he didn't say it very convincingly.

Ten penalties were called against the Bills in all, for 66 yards; six against the Colts for 34 yards.

The Bills went 94 yards to score in the second quarter on a one-yard plunge by fullback Roosevelt Leaks. Nick Mike-Mayer's conversion attempt was aborted by a bad snap, leaving the Colts with a 10-6 lead.

After the Colts scored seven points following the disputed play, Mike-Mayer of the Bills kicked a 49-yard field goal in the second quarter to reduce Baltimore's lead to 17-9.

The Bills got down to the Baltimore three in the fourth quarter, but on fourth and three, Coach Chuck Knox of the Bills chose to go for a 20-yard field goal by Mike-Mayer instead of trying for a touchdown. It narrowed the Colts' margin to 17-12.

Knox said about going for three points instead of a field goal: "We had to take the three points, and then come back and try to get a touchdown."

Cornerback Kim Anderson of the Colts snuffed out the Bills' last hope by intercepting Joe Ferguson's pass in the end zone with four seconds remaining.

"We had our chances and didn't capitalize on them," Ferguson said. "We were hurt by penalties, some of them questionable."

"Some of our players knew if they were holding -- if they were."

Guard Conrad Dobler was penalized twice for holding and guard Reggie McKenzie once.

Linebacker Isiah Robertson of the Bills criticized the penalties and charged that "the officials never did 'finger' which of our guys was supposed to have chucked Carr on Simpson's interception."

Dobler said, "I had not been called for holding in five previous games this season. I don't agree I was holding today. I can't complain because I've got to play under those officials sometime again this season.

"The second penalty against me came on a very, very crucial third-down play.

"I was held by defenders a couple of times and my face mask was grabbed once, but the Colts were not penalized in any of those instances."

Dobler alluded to a holding call against him in the third quarter. Ferguson got the Bills moving 33 yards to the Baltimore 47, then the penalty against the guard sent Buffalo back to its 43 and the drive faltered.

Baltimore (4-2) moved within a game of the Bills and the New England Patriots, both 5-1 in the AFC East, because the Colts did not fritter away their opportunities in the first quarter.

Rookie running back Joe Cribbs of Auburn barely won rushing honors for the Bills, with 76 yards to 74 for veteran Joe Washington of Baltimore.

Quarterback Jones tried only 21 passes for the Colts, completing 10 for 206 yards and the touchdown to Siani. Ferguson hit on 17 of 36 passes for 210 yards and no touchdowns.