CINCINNATI -- Chad Johnson set a merry mood, pulling championship T-shirts, caps and footballs out of his Santa bag and flinging them into the stands after his first-half touchdown.

Then the Bengals got really generous.

Playing as a division champion for the first time in 15 years, the Bengals let a game and a first-round playoff bye get away yesterday. Terrence McGee returned a kickoff and an interception for a touchdown, rallying the Buffalo Bills to a 37-27 victory.

McGee's 46-yard interception return with 35 seconds left sent 65,485 fans filing glumly out of the stadium in their orange-and-black Santa hats, stunned by what they'd just seen.

For the first time all season, the Bengals (11-4) lost a game they were expected to win, against a team that hadn't won on the road all season. They needed a win to keep pace with Denver for the AFC's No. 2 seed and a first-round playoff bye.

"Oh, well. Can't be great all the time," receiver T.J. Houshmandzadeh said. "If anybody thought we were that great, this brings them back to earth."

The Bengals clinched the AFC North title a week earlier in Detroit and wished for an afternoon of revelry in front of the home crowd. Instead, they got a reminder of what can happen when they let a game turn into a shootout.

"We need to truly learn from this and know what playing like this can get us," offensive guard Bobbie Williams said. "It can get you an 'L' and when you get to the playoffs, getting an 'L' means you're out of it."

The Bills (5-10) have been out of it for a long time, losing their previous five games. McGee and Kelly Holcomb led them to a feel-good win at the end of a disastrous season, one that has players wondering what ownership will do in the offseason.

"Nobody gave us a chance to beat these guys," said Holcomb, who was 24 of 31 for 308 yards. "We hadn't won on the road. It definitely leaves a good taste in your mouth."

McGee had five kickoff returns for 220 yards, including his 99-yard sprint down the left sideline that sparked the comeback late in the third quarter.

He set a club record with three kickoff touchdowns last season, and now owns the Bills' career mark.