DENVER — Richie Saunders scored 25 points, Keba Keita had 10 points and three blocked shots and No. 6 seed BYU held off No. 3 seed Wisconsin 91-89 in the second round of the East Region on Saturday night.Trevin Knell added 14 points and Egor Demin added 11 points, eight rebounds and eight assists for BYU (26-9). The Cougars advance to the Sweet 16 for the first time since 2011 and will face the winner of Sunday’s Alabama-Saint Mary’s matchup.John Tonje scored 37 points on 10-of-18 shooting from the field but missed a shot to send it into overtime with one second left. John Blackwell finished with 21 points, Max Klesmit had 12 and Steven Crowl contributed 10 for the Badgers (27-10).BYU led by 13 early in the second half, but the Badgers surged to cut the deficit to 52-48. The Cougars responded to lead 70-56 with 10:25 left.Wisconsin rallied to get within 75-68, but Knell drained another 3-pointer, Keita split a pair of free throws and Klesmit answered from deep to make it 79-71 with 6:46 remaining.Soon after, Keita converted a three-point play to restore the double-digit lead. The Badgers trimmed it to eight on Klesmit’s fourth 3-pointer with 4:27 left but Saunders muscled his way in for a layup, Keita blocked Blackwell’s layup and Demin’s 3-pointer made it 89-78.