Spokane, WA (SportsNetwork.com) - North Dakota State starts a trio of seniors, but a freshman came through in the final minute of overtime as the Bison claimed their first NCAA Tournament win in school history.
Carlin Dupree came off the bench when Taylor Braun, the Summit League Player of the Year, fouled out with 1:18 remaining in the extra session.
Dupree hit a pair of free throws seconds after stepping onto the floor, which gave North Dakota State a lead, then followed that with a tough layup in traffic to help the 12-seed Bison to an 80-75 upset win over fifth-seeded Oklahoma in the second round of the NCAA Tournament.
"It was a big shot, obviously, for the team," Dupree said of the layup. "I didn't want this to end for these guys, so I see how hard we worked and we stayed together as a team and I'm excited that we pulled it off."
Lawrence Alexander finished with a career-high 28 points to pace North Dakota State (26-6), while Marshall Bjorklund scored 13 points with six rebounds and Braun tallied 11 points on just 3-of-11 shooting.
The Bison will face fourth-seeded San Diego State on Saturday in the third round.
Cameron Clark scored 22 of his 25 points in the second half and overtime in his final game for Oklahoma (23-10) and Isaiah Cousins netted 17 points with eight rebounds.
Jordan Woodard added 13 points and Buddy Hield, a second-team All-Big 12 selection, contributed nine points on 4-of-14 shooting.
North Dakota State, the nation's top shooting team entering the tournament at 50.9 percent, connected on 52.9 percent of its field goals in the win.
Cousins made a pair of free throws to give the Sooners a 62-61 lead with 90 seconds left in the second half, which was Oklahoma's first advantage since it was 29-28 late in the first.
Clark added a jumper and Woodard knocked in 1-of-2 from the line to cap an 8-0 run for a 65-61 edge.
Braun then hit two free throws on the Bison's next possession after a Cousins foul 40 feet from the basket with 30 seconds to go in regulation. Cousins split a pair at the line to push the margin to 66-63 and Alexander tied the game after hitting a 3-pointer with 11.2 seconds left.
"Actually, the play was drawn up for Taylor," said Alexander on his game-tying 3-pointer. "Supposed to be a quick iso, but coming out of the huddle I told him if you don't have anything I'll be right there in the right wing."
Hield missed a wide-open trey from the corner following a timeout, then Woodard corralled the rebound and missed a jumper of his own with three seconds remaining. Cousins grabbed the Woodard miss, but his layup underneath was off the mark as time expired.
Bjorkland and Alexander both made baskets to open the overtime period and give the Bison a 70-66 lead.
After Ryan Spangler split a pair at the line, Clark hit a three to tie the game at 70-70 with under three minutes left in OT.
Braun then drove the lane and made an acrobatic layup to give North Dakota State an advantage. He fouled out on the other end of the floor after slapping Clark on the wrist with 1:18 remaining.
Clark hit the subsequent free throws, then Dupree knocked in two from the line on the next Bison possession before racing down the floor to convert a layup with two Sooners in his face for a 76-72 advantage with under a minute to go.
Woodard turned the ball over on the next Oklahoma touch and Alexander was 4- for-4 from the line down the stretch to seal the upset.
"Well, it was a tough ball game to not win," Oklahoma coach Lon Kruger admitted. "Credit North Dakota State. I thought (Bison) coach Phillips and his guys did a terrific job and did what they needed to down the stretch and credit to them for that."
Earlier, Cousins knocked down a jumper to give the Sooners a 29-26 lead with 3 1/2 minutes left in the first half.
Kory Brown answered with a layup that ignited an 11-0 run to end the stanza for the Bison and stake them to a 37-29 lead at the break.
North Dakota State shot a blistering 15-of-24 (62.5 percent) from the field in the opening half compared to 11-for-34 (32.4 percent) shooting from Oklahoma.
This is the second time in school history that North Dakota State has made the NCAA Tournament. The Bison were a 14 seed in 2009 when they dropped a first- round game to Kansas ... The win matched the NDSU school record of wins set in 1924-25 and 2008-09 ... The Bison improved to 1-7 against members of the Big 12 Conference in the Division I era (since 2004-05) ... Oklahoma shot 25-of-72 from the field and 12-for-30 from beyond the arc ... Alexander pulled down eight rebounds in the win.
03/21 01:52:10 ET