Trey Alexander made two free throws with 1.9 seconds left for Creighton, which will play for the title Wednesday against either No. 14 Arizona or No. 17 San Diego State.
The Bluejays (6-0) and Razorbacks (4-1) played an electrifying second half worthy of a March Madness matchup. Arkansas has reached the Elite Eight in consecutive seasons and Creighton got to the second round last year after advancing to the Sweet 16 in 2021.
Ryan Kalkbrenner scored 21 points, Baylor Scheierman 20 and Alexander 12 for the Bluejays, who had a 12-point lead late in the first half.
Anthony Black scored 26 points, Ricky Council IV 24 and Trevon Brazile 17 for the Razorbacks.
There were 10 lead changes and the game was tied 10 times in the second half.
Nembhard made two free throws after the Arkansas bench was whistled for a technical foul with 13:57 to go for a 53-53 tie. Creighton was in the double bonus for the final 13 minutes.
Nembhard, the shortest player on the floor at 6 feet, drove for a dunk and a 79-76 lead with 2:34 to go. Brazile answered with a 3-pointer the next time down the floor to tie it at 79.
Kalkbrenner made a reverse jam with 1:20 left to give the Bluejays the lead for good at 83-81.
After Scheierman made two free throws for an 87-84 lead with 16 seconds left, Council missed a corner 3 and Nembhard rebounded and was fouled. He made one of two free throws and Black came down the floor and drained a straight-on 3 to pull Arkansas within one. Alexander then made his two insurance free throws.
Creighton ran to a 12-point lead with 1:43 to go in the first half before the Razorbacks closed with a 6-0 run, capped by Trevon Brazile’s thunderous dunk on an alley-oop pass from Anthony Black.
Creighton: The Bluejays’ free-flowing offense produced three players in double digits by halftime: Nembhard with 13 points, Scheierman 11 and Kalkbrenner 10.
Arkansas: This was a big step up in competition for the Razorbacks. They opened the season with easy home wins against North Dakota State, Fordham and South Dakota State, and then beat winless Louisville by 26 points in their Maui opener.
Creighton will face either the Wildcats or the Aztecs in what should be another March Madness-worthy game for the title.
Arkansas will face the SDSU-Arizona loser for third place.
AP college basketball: https://apnews.com/hub/college-basketball and https://apnews.com/hub/ap-top-25-college-basketball-poll and https://twitter.com/AP- Top25