While Ager had a good night, Florida's Anthony Roberson suffered through one of his worst games. Roberson, who chose Florida over Michigan State when he was heavily recruited by both schools, failed to score for the first time all year and missed all five of his three-point shots.
"I love that kid," Izzo said. "I get no pleasure out of anything (negative) with Anthony Roberson. I know his high school coach real well. I recruited him for four years."
Chris Hill made a three-pointer midway through the first half to trigger a 10-0 run that gave Michigan State the lead for good. Ager's three-pointer capped it and made it 30-20 with 4:23 left before halftime.
Ager had a three-pointer and two free throws in a 13-4 tear at the start of the second half to provide a 50-31 cushion with 9:52 remaining. The Gators had just two baskets -- both by Justin Hamilton -- in the first 10 1/2 minutes of the second half.
"It feels really good right now," Hill said. "We're going to enjoy this moment for as long as we can. We're not satisfied with this."
Michigan State is in the Sweet 16 for the fifth time in six years and will face defending national champion Maryland on Friday night in San Antonio. The Spartans reached the Final Four from 1999-2001 while the Terrapins made it in 2001 and 2002.
Ager was not the only freshman to play well as Slovenian Erazem Lorbek scored 12 points and grabbed seven rebounds. Ager and Lorbek had struggled through most of the season, although they have played well recently.
"Ours have come along a little slower than Florida's," Izzo said. "Our freshmen bobbed and weaved through things."
Florida's more heralded freshmen struggled. Roberson, Matt Walsh and Christian Drejer combined to score eight points.
Izzo scolded a Florida reporter for writing about how Davis won the state's Mr. Basketball award over Roberson, who many felt was slighted for the honor because he chose Florida over the state school. Roberson and his family were also harassed when he chose Florida.
"I was disappointed that that someone would try to make a thing about him (Roberson)," Izzo said. "He's had an incredible year. Would I have liked to have him? Yes. Did I think that he was the best player in Michigan? Probably so. I don't think anybody was happy about that."
Florida shot 37 percent, including five-of-16 effort in the second half. The high-scoring Gators were held to their lowest point total of the season.
"The bottom line is it's hard for us to win when we're not shooting the ball well," Florida Coach Billy Donovan said.
Michigan State was able to take the fans in Tampa out of the game, which was a major area of concern. Many in the arena left midway through the second half.
"To come down here and beat what I think is a very good basketball team in their home environment is something special," Izzo said. "We just got after it, defended, looked pretty solid and that was enjoyable for me."
The Spartans' defensive effort was keyed by Kelvin Torbert, a McDonald's All-American who has struggled in his two years. Torbert was efficient in physically defending Bonner and Hill and Ager did an excellent job in chasing Florida's shooters.
The Gators drew within 51-36 on a jumper by Walsh. Ager dunked to cap a run of 11 straight points for the Spartans for a 62-36 bulge with 5:11 to go.
Florida ended its season with losses in four of its final games and has exited the NCAA Tournament in the second round or earlier in every year since the national title game appearance.
"You're going to have more heartbreaking losses in the NCAA Tournament than runs to the Final Four," Donovan said. "There's a lot of coaches who never get a chance to experience one."
Gators guard Brett Nelson failed to score and missed all four shots in his final game. Nelson scored 11 points in Florida's 89-76 loss in the title game.