(Photo credit: Kirby Lee-Imagn Images)

A No. 1 seed has been eliminated while a No. 11 seed reached the Sweet 16, but the overall dearth of upsets through the first two rounds of the NCAA Tournament has left sportsbooks sweating.

'It was a chalky opening weekend in the NCAA Tournament with favorites winning 22 straight games from Thursday to Saturday,' BetMGM senior trader Michael Ranftle said. 'The sportsbook will be looking for a few upsets in the Sweet 16.'

No. 1 overall seed Duke survived a first-round upset bid from Siena and remains the strongest favorite to reach the Final Four at -110. Part of that is due to the fact that the Blue Devils will face the third-highest remaining seed in No. 5 St. John's on Friday.

However, Duke has slipped to the third-shortest odds to win the national title, moving from the -300 pre-tournament favorite to -425 on Monday. The Blue Devils are now behind Michigan (+300) and Arizona (+325) at BetMGM.

The Wolverines have been dominant in blowing through No. 9 Howard and No. 9 St. Louis in the Midwest region by an average of 22 points. Michigan will face No. 4 Alabama in the Sweet 16 on Friday. Arizona blew out Long Island to open its West region action before handling a much tougher test against No. 9 Utah State on Sunday night. The Wildcats will also face a fourth seed in Arkansas on Thursday.

DraftKings is currently offering Arizona as the slight title favorite at +330 ahead of Michigan at +340 and Duke at +370. The Wildcats have also been backed by the most total national champion bets (10.7%) and money (18.1%) at BetMGM.

A notable good result for sportsbooks was the elimination of Miami (Ohio), which had been BetMGM's biggest liability. In general, upsets leave books exposed.

'On the futures book, St. John's and Arkansas are the biggest remaining liabilities to cut down the nets, while all the 1-seeds are positive outcomes,' Ranftle said.

The book reported that it has received a $100,000 wager on Purdue to reach the Final Four that would pay $600,000. The No. 2 seed in the West, the Boilermakers will play No. 11 Texas on Thursday before a potential Elite Eight showdown against Arizona or Arkansas. Purdue has also moved from +1400 before the tournament to win the national title to +1200 by Monday.

The upset of the reigning national champion Gators left No. 2 Houston as the top remaining seed in the South. If the Cougars can get by No. 3 Illinois on Thursday they would face the winner of No. 4 Indiana against No. 9 Iowa -- the second-highest remaining seed.

Houston's title odds have shortened from +900 to +700 since the tournament began. BetMGM has taken a $50,000 bet at +900 on Houston to win the title that would pay $450,000. That has contributed to the Cougars being backed by 9.3% of all money wagered on the national champion.

Houston has moved from +1200 to +700 at DraftKings since the tournament began. Iowa has seen the biggest movement, shifting from +30000 to +12000 to win the title, while Texas has moved from +40000 to +30000.

--Field Level Media