A bettor walked up to the counter at the MGM Mirage sports book Sunday morning with a question -- "How much can I bet?"

"I told him, 'whatever you like,'" said Jay Rood, MGM vice president of race and sports. "He took the [Dallas] Cowboys for six figures."

Ouch.

Big money was flying all around Vegas on the opening week of the NFL ... and the books kept a ton of it.

Jay Kornegay, vice president of race and sports at the Westgate SuperBook, told ESPN that it was the best Sunday of his 20-plus-year bookmaking career. The story was the same across town: The books cleaned up.

"We actually won all 10 games in the early slate," said Marc Nelson, sports book director at the Aliante casino. "That doesn't happen very often."

NFL underdogs went 8-2 against the spread in Sunday's early slate and finished 10-3 ATS on the day. The Cowboys -- thanks in part to three Tony Romo interceptions -- were one of the three 'dogs not to cover. Dallas lost 28-17 to the San Francisco 49ers as 3-point home underdogs.

The Miami Dolphins' upset of the New England Patriots and Atlanta Falcons' upset of the New Orleans Saints were boons for the books. Nelson at the Aliante said the Dolphins' 33-20 win over the Patriots was his biggest win on Sunday. William Hill's book reported Friday that 91 percent of the bets on the New Orleans-Atlanta game were on the favored Saints. The Falcons won in overtime.

The knockout punch for bettors came in the night game. John Avello, executive director of the Wynn sports book, said his shop needed the Indianapolis Colts in a "big six-figure decision." Rood said an hour before kickoff that eight times more money had been bet on the Broncos than the Colts. The Broncos led 24-0 in the first half, but failed to cover as 8.5-point favorites in a 31-24 win.

The scary part? The day could have been even more lucrative for the books. The Philadelphia Eagles, favored by 10 over the Jacksonville Jaguars, returned a fumble with 1:23 to play to cover the spread in a 34-17 win. The Jaguars had jumped out to a 17-0 lead, but were outscored 20-0 in the fourth quarter.

"If the Jaguars would have been able to salt it [the cover] away, it could have been our best day ever," said Rood. "Giving a little back isn't a bad thing right now. We don't want to stick everyone in a corner too much early in the season. Overall, it was a pretty damn good day."

Move on Oregon

A group of professional bettors moved in on Oregon against Michigan State on Saturday afternoon, pushing up the point spread from Ducks minus-12.5 to as high as minus-14.5 before kickoff. SuperBook head football oddsmaker Ed Salmons described the influential bettors as a "respected group that has had some success betting on sports."

That group caught a late break. After trailing at halftime, Oregon scored the game's final 28 points, including a 14-yard touchdown run on a fourth-and-2 with 1:25 to play that covered the spread for the Ducks.

It was that kind of weekend for the Big Ten. Ohio State lost to Virginia Tech 35-21 as a 10-point favorite. Michigan was shut out by Notre Dame 31-0, and Nebraska found itself tied late in the fourth quarter against 35-point underdog McNeese State. Overall, Big Ten teams combined to go 2-11 ATS on Saturday.

Early college football line moves

Georgia at South Carolina, 3:30 p.m. ET: The best game on the board in Week 3 saw some early line movement. Vegas sports book CG Technology opened the Bulldogs as 2.5-point road favorites over the Gamecocks. The line quickly jumped to UGA minus-4.5.

The perception of these two SEC rivals has changed significantly early in the season. In July, Vegas sports book operator CG Technology made South Carolina a 4.5-point favorite over Georgia in one of its Games of the Year lines. But the Gamecocks lost a ton of respect in an opening blowout loss to Texas A&M. Plus, Georgia was impressive in its opening win over Clemson and had an extra week to prepare for the Gamecocks. Bulldogs coach Mark Richt may need it. He is 2-6-1 ATS versus Steve Spurrier at South Carolina.

Early Week 3 college football action