Wagering on the NFL and playing fantasy football share an important characteristic.

In both cases, in the midst of the most innocuous game, a field goal or a touchdown of little apparent consequence can be a source of anguish or elation.

Yesterday, the betting fate of an excruciatingly ho-hum game was decided by a score that will go largely unnoticed in today's box scores - except by the bettors who made or (more probably) lost money.

The lowly Detroit Lions, deservedly 13-point underdogs to Cincinnati, were trailing by 16 when they mounted a drive in the closing minutes with Daunte Culpepper in a mop-up role at quarterback.

After Culpepper scrambled and passed the Lions downfield, running back Kevin Smith scored on a 2-yard run with 1 minute, 36 seconds left to set the final score at 23-13, delighting Smith's fantasy owners and, of course, allowing Detroit to beat the spread despite falling to 2-10 in the standings.

In betting parlance, such a late score is a "backdoor cover." And it stung a lot of bettors because in a season when few teams can be counted on to cover the spread, the Lions have been a team that bettors have been counting on to not beat the spread. Before yesterday, Detroit was 2-8-1 against the spread.

"It had a big effect on the parlays because just about anyone who was betting more than one game was taking Cincinnati," said Jay Rood, director of the race and sports books at the MGM Mirage casinos in Las Vegas.

"And if it hadn't been Culpepper in there at the end, it may have been a lot different," Rood said. "If it's a quarterback who's been playing [all game], he may not be as enthusiastic as Culpepper, who feels he has to showcase himself to convince teams to bring him in next year."

Not quite as dramatic, but similar in effect, was the fourth-quarter field goal by Josh Brown that narrowed St. Louis' margin of defeat to Chicago to 17-9. The Bears were giving nine points, so Brown's kick - the final score of the game, albeit with about 10 minutes left - allowed the Rams to beat the spread by one point.

Yesterday wasn't a great one for pro bettors or the public.

Cash had flowed toward surging Tennessee (getting six to seven points against Indianapolis) and Houston (giving as many as two against Jacksonville). Neither the Titans nor the Texans were able to beat the spread.

Contact staff writer Bill Ordine

at 215-854-2939 or wordine@phillynews.com.