Gilbert made a pair of free throws with 44.9 seconds left to give Iowa State the lead for good. He shot 12 of 14 from the line.
Dishon Jackson had 12 points and six rebounds, and Milan Momcilovic scored 10 for Iowa State.
Malachi Smith scored a career-high 22 points for Dayton.
Takeaways
Iowa State: Point guard Tamin Lipsey, a preseason All-Big 12 first-team pick, was limited to six points and two assists in 16 minutes. He fouled out with 2:42 to play.
Dayton: The Cyclones entered leading the country in scoring defense at 58.8 points per game, but the Flyers shot 58% (29 of 50) from the field and had four players score in double figures.
Key moment
Gilbert grabbed an offensive rebound and was fouled by Dayton's Zed Key as he went up for a putback with 44.9 seconds left. After a review, the foul was upgraded to a flagrant-1. Gilbert knocked down both free throws, then made it a four-point possession with a driving layup and high finish off the glass to give the Cyclones an 85-81 lead with 26.8 seconds remaining.
Key stat
The Cyclones made 25 of 29 free throws for the game and shot 60% (15 of 25) from the field in the second half to overcome a 41-37 halftime deficit.
Up next
Iowa State will play Colorado for fifth place Wednesday, while Dayton will meet No. 2 UConn for seventh place.
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Credit: AP
Credit: AP
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Credit: AP