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.

Tonje, who had 41 points in the win over Arizona, hit a 3-pointer from the left corner to end a scoring drought of almost 4 1/2 minutes and put Wisconsin up 74-72 with 5:08 left.

Abdul Hakim hit a 3-pointer to put UTRGV up 61-54, but the Vaqueros went more than three minutes without scoring before Tommy Gankhuyag’s 3-pointer put them in front 64-61 with just over 12 minutes to go.

Blackwell, who had 15 of Wisconsin’s first 20 points after the break, hit a 3-pointer to put the Badgers up 68-66.

UT Rio Grande Valley hit 20 of 32 shots in the first half (62.5 percent), including 8 of 17 from 3-point range. Wisconsin stayed close by hitting 14 of 16 free throws before the break.