Kentucky Basketball Andrew Harrison
Kentucky Wildcats guard Andrew Harrison (5) reacts during the second half against the Cincinnati Bearcats in the third round of the 2015 NCAA Tournament at KFC Yum! Center. Reuters/Brian Spurlock-USA TODAY Sports

The first weekend of March Madness featured the usual upsets, but the biggest favorites in the 2015 NCAA Tournament survived the second and third rounds. Kentucky, Arizona, Duke, and Wisconsin all advanced after starting the tournament with the best betting odds to win the college basketball national championship.

No.1 overall seed Kentucky entered March Madness as heavy favorites to win the title, and they’ve done nothing through two games to change that perception. The Wildcats breezed by Hampton, 79-56, in the opener, and had little trouble in their 64-51 victory over Cincinnati. Kentucky’s two wins helped them make history, becoming the first team to ever start the year 36-0.

Duke and Wisconsin, the other No.1 seeds remaining, are tied for the third-best odds. The Blue Devils won both games by at least 19 points, and the Badgers topped Oregon by seven points in a relatively close Round-of-32 contest. Villanova became the first No.1 seed to lose, falling to No.8-seeded NC State on Saturday night.

Arizona remains the second favorite, even as a No.2 seed. After scoring a tournament-high 93 points in their blowout win over Texas Southern, Arizona beat Ohio State by 15 points.

Michigan State has the best odds of any team seeded No.3 or lower. The No.7-seeded Spartans defeated No.2-seeded Virginia on Sunday, reaching the Sweet 16 for the seventh time in eight years. Travis Trice has been one of the best players in the tournament, averaging 19 points, 2.5 rebounds and 4.5 assists in two games for Michigan State.

Notre Dame is the one team that has seen their betting odds noticeably decrease, since being selected as the No.3 seed in the Midwest region, going from 25/1 odds to 33/1 odds. The Fighting Irish have a difficult road to the Final Four, likely having to go through Kentucky in the Elite Eight if they get beyond their matchup with Wichita State.

No.5-seeded West Virginia, No.6-seeded Xavier and No.11-seeded UCLA enter the Sweet Sixteen as the biggest longshots with 100/1 championship odds. UCLA pulled off an upset in the Round of 64, but they were favored against No.14-seeded UAB in their second contest. Xavier has yet to face a team that's been seeded higher than them, beating No.11-seeded Ole Miss and No.14-seeded Georgia State.

Sixteen teams began the tournament with 50/1 odds or better to win the national championship. Five of them have already been eliminated.

Below are the championship betting odds for the 2015 NCAA Tournament, ahead of the Sweet 16, courtesy of Bovada.lv.

Kentucky 1/1

Arizona 13/2

Wisconsin 8/1

Duke 8/1

Gonzaga 12/1

Michigan State 14/1

Utah 20/1

Louisville 25/1

Oklahoma 25/1

North Carolina 33/1

Notre Dame 33/1

Wichita State 33/1

NC State 50/1

UCLA 100/1

West Virginia 100/1

Xavier 100/1