John Blackwell scored 20 of his career-high 30 points in the second half and graduate transfer John Tonje added 19 as No. 19 Wisconsin rallied to hold off stubborn UT Rio Grande Valley 87-84 on Monday night in Madison, Wis.Wisconsin (5-0), which trailed 52-48 at the half, went without a field goal over the game’s final 4:23 and scored its last 11 points from the free throw line. The Badgers, who entered No. 1 in the nation in free throw percentage (90 percent), finished 27-of-32 from the line.Tonje, who played at Missouri last season, hit four consecutive free throws to put the Badgers in front 80-75 with 3:34 left. He hit two more free throws to make it 85-81 with 1:14 remaining and finished 10-of-10 at the stripe.DK Thorn hit a deep 3-pointer with just over a minute left to pull the Vaqueros within 85-84. Max Klesmit missed a jumper on Wisconsin’s next possession, but UTRGV’s Hasan Abdul Hakim missed a hurried jumper from the lane with time running out.Blackwell hit two free throws with 2.1 seconds left to make it 87-84.Wisconsin entered the rankings this week after a 103-88 victory Friday over Arizona, which dropped from ninth to No. 17.Abdul Hakim had 19 points and K.T. Raimey had 13 for the Vaqueros (3-3), who had won three straight.