LAS VEGAS — For months, bookmakers watched money flow in on a perennial underdog that was turning into a public favorite. There were countless bets on the Browns to win their division and the Super Bowl in addition to tickets on Baker Mayfield to be MVP.

All summer, bettors were hot on Cleveland. And then, in a TV sitcom twist, Mayfield showed up on the season’s first Sunday and played quarterback like Valerie Bertinelli or Betty White.

After an offseason of trash-talking and Daniel Jones-bashing, Mayfield was humbled in a 43-13 loss to Tennessee. The Browns’ top dog was sacked five times and intercepted three times — and there were no Odell Beckham Jr. sightings in the end zone — in an embarrassing blowout.

“It’s like the Browns got a dose of reality,” Westgate SuperBook director John Murray said. “Everybody was on Cleveland. The Titans were the biggest winner for us.”

The Browns’ flop as 5½-point favorites was a positive start for bookmakers, but it was just the start. And the big picture could tell a different story.

“I don’t think the Browns were overhyped. I still think they can be good,” William Hill sportsbook director Nick Bogdanovich said. “It’s not the end of the world. It’s just one game in a long NFL season.”

Bogdanovich said it was a losing Sunday for William Hill. A few results went the books’ way. The Jets blowing a 16-0 lead in a 17-16 loss to the Bills was especially profitable for New Jersey books. It also helped that the Redskins, 10-point underdogs, scored a last-minute touchdown to cover in a 32-27 loss to the Eagles.

But the day’s most popular favorites — Baltimore, Dallas, Kansas City and New England — coasted to point-spread covers to buoy the betting public. Resisting overreactions to Week 1 is an annual theme, yet some results did mandate at least minor adjustments to odds and power ratings.

The weekend started with the Patriots signing wide receiver Antonio Brown immediately after the enigmatic star was released by the Raiders. The weekend ended with the Patriots putting a 33-3 beating on the Steelers.

William Hill initially lowered Super Bowl odds on New England from 6/1 to 5/1, and the number had dropped to 7/2 as futures money poured in on the Patriots. Brown’s subtraction means a downgrade for Oakland, which opened its season Monday night.

“Brown is going to take the Patriots offense to the next level,” Murray said. “The perception is the Raiders are a team in complete disarray.”

William Hill opened the Patriots as 14½-point favorites at Miami in Week 2, and the line was up to 17 by Monday morning. The Dolphins debuted as 7-point home underdogs and were on the wrong side of a 59-10 rout by the Ravens.

“Miami just looks hopeless right now,” Murray said. “You don’t want to overreact to one game, but Miami looks like a team that’s punting on the season. The Dolphins are going to be terrible.”

Baltimore is a 13½-point favorite over Arizona, after the SuperBook last week posted a lookahead line of 9½. The Ravens’ Lamar Jackson passed for 324 yards and five touchdowns in Week 1, prompting Caesars oddsmakers to move Jackson from 50/1 to 18/1 to win MVP.

The Jaguars lost quarterback Nick Foles to a broken clavicle early in their 40-26 loss to the Chiefs. Foles, expected to miss about 10 weeks, will be replaced by rookie Gardner Minshew. The drop-off from Foles meant a 6½-point adjustment on Jacksonville, which was getting three points at Houston on the lookahead line and is now getting 9½.

The Colts appear to be OK with Jacoby Brissett replacing Andrew Luck. Brissett passed for two touchdowns with no interceptions in Indianapolis’ 30-24 overtime loss to the Chargers, who did not miss running back Melvin Gordon during his contract holdout.

After watching the Cowboys crush the Giants, 35-17, oddsmakers boosted Dallas’ power rating and did the opposite with the Giants, who allowed Dak Prescott to pass for 405 yards and four touchdowns with no interceptions or sacks.

“The public is going to be all over the Cowboys,” Murray said.

Eli Manning is not the issue with the Giants, who have a big problem on defense. The SuperBook lookahead line for Week 2 showed the Giants as 1½-point favorites over the Bills. After the teams’ disparate results, Buffalo is favored by 2½.

“The favorite flipped, and you can see why,” Murray said. “I really like a lot of what I see with the Bills. The Buffalo defense is really good.”

Adam Gase and Sam Darnold can attest to that. The Jets opened as 2½-point home ’dogs in Monday’s matchup against the Browns, who remain in the favorite’s role despite a 30-point loss.