Las Vegas sportsbooks didn't win every decision from Sunday's 12-game NFL slate. Some Bookmakers had to settle for coming out ahead in only 11 of them.

The Westgate SuperBook and Caesars Palace sportsbooks each went 11-1 on Sunday and enjoyed their best week of the season as 10 underdogs covered the spread, with eight pulling outright upsets.

"We didn't run that hot," said Jason Simbal, vice president at sportsbook operator CG Technology, who said his book lost two decisions, "but we got what we needed."

Indeed, especially in the night game between the heavily favored Denver Broncos and the New York Giants.

A bettor at CG Technology placed two $200,000 wagers on the Broncos, laying 13 and 13.5 points. An hour before kickoff of the night game at MGM sportsbooks, 12 times as much money had been bet on the Denver Broncos as had been bet on the underdog Giants.

The Giants won 23-10, becoming the second 13-point underdog to win outright on Sunday. The Miami Dolphins upset the Atlanta Falcons as 13-point underdogs in the early slate. It's the first time that multiple 13-point favorites lost in the same day since Dec. 9, 1973 (Week 13), according to ESPN Stats & Information.

The Minnesota Vikings' upset of the Green Bay Packers produced the biggest win of the morning slate for the books, and the Pittsburgh Steelers sealed a winning day for the casinos by handing the favored Kansas City Chiefs their first loss of the season.

"The Packers and Chiefs losing, those two games dwarfed everything else," Ed Salmons, assistant manager at the Westgate, said late Sunday afternoon. "Saints-Lions was the only one we lost."

Just three weeks ago, underdogs also went on a hot streak, covering the spread in 10 of 13 games on Sept. 24 and leading the books to what some said was their best Sunday ever.

This Sunday was right there with it.

"Second-best Sunday of the season," Michael Grodsky, vice president of marketing for William Hill's Nevada sportsbook, told ESPN. "Week 3 was just historic for us."