MADISON, Wis. _ For the first two quarters Saturday afternoon, a crowd of 80,584 fans and a national TV audience must have wondered why Wisconsin was ranked No. 10 in the polls and the prohibitive favorite to win the Big Ten West Division title.
UW's offense, so efficient in its previous outing at BYU, suffered three turnovers and a general malaise save for one touchdown drive.
Then came the second half.
UW dominated play on both sides of the line of scrimmage, with the offense contributing three scores and the defense one, to turn a three-point deficit into a 21-point lead in a span of 22 minutes 44 seconds of game time.
The Badgers settled for a 33-24 victory over the Wildcats in the teams' Big Ten opener.
UW (4-0, 1-0 Big Ten) prevailed without senior tight end Troy Fumagalli, who was held out because of a minor left leg injury.
Next up for UW is a road test against Nebraska (3-2, 2-0), which has regrouped after a 1-2 start with victories over Rutgers and Illinois.
Northwestern fell to 0-1 in the Big Ten and 2-2 overall.
UW entered the weekend No. 1 in the Big Ten in scoring (43.3 points per game), No. 1 in rushing offense (275.3 yards per gme), No. 2 in total offense (511.0 yards per game) and No. 1 in third-down conversions (57.9 percent).
The Badgers' struggled to move the ball for most of the first half against a suspect Northwestern defense before awakening.
Quarterback Alex Hornibrook, who completed 18 of 19 attempts for 256 yards and four touchdowns at BYU, never found a rhythm in the opening half Saturday. He was 5 of 11 for 48 yards, with two interceptions, in the first half as Northwestern took advantage of excellent field position to score twice for a 10-7 lead.
Hornibrook responded in the second half, however, by completing 6 of 8 passes for 149 yards and a touchdown. He entered the day with one interception in 70 attempts and threw two in his first eight attempts Saturday.
Tailback Jonathan Taylor entered the game averaging 8.3 yards per carry and 146.0 rushing yards per game. He gained 62 yards and a touchdown on 11 carries in the first half and finished 80 yards and two touchdowns on 19 carries.
Justin Jackson averaged 34 carries and 150.5 yards in victories over UW in 2014 and '15. UW last season held Jackson to 42 yards on 13 carries en route to a 21-7 victory.
He was held in check again Saturday and finished with 25 yards on nine carries.
Northwestern quarterback Clayton Thorson entered the day 37 of 72 (51.4 percent) for 168.5 yards per game in two starts against UW. He had three touchdown passes Saturday, including two in the final 4 minutes 46 seconds to pull the Wildcats within 31-24 with 2:53 remaining. Thorson finished 29 of 45 for 219 yards. He also threw two interceptions.
Northwestern managed a modest 117 yards on 35 plays in building a 10-7 halftime lead. UW's defense held the Wildcats to 23 yards on 19 plays in the third quarter when UW scored twice for a 21-10 lead.
UW's defense entered the day with eight sacks in its first three games. The Badgers got to Thorson eight times Saturday, including three by linebacker Garret Dooley.
UW stumbled out of the gate.
Hornibrook hit Jazz Peavy in the left flat but cornerback Trae Williams came up to force a fumble and he recovered the ball at the UW 24 just eight seconds into the game.
UW's defense recorded a three-and-out, however, with linebacker Leon Jacobs dropping Jackson for a 1-yard loss on third and one from the 16.
The Wildcats settled for a 34-yard field goal and a 3-0 lead with 13:25 left in the quarter.
A.J. Taylor fumbled the ensuing kickoff but UW recovered at its 19 to avoid a second consecutive turnover.
The Badgers punted after picking up two first downs and Anthony Lotti pinned the Wildcats at their 7 with a 48-yard punt.
UW's defense did its job with a three-and-out, with redshirt freshman end Isaiahh Loudermilk sacking Thorson for a 10-yard loss to the 11 on third down.
A 36-yard punt gave UW the ball at the Northwestern 47 and the Badgers needed seven plays to take the lead.
Taylor carried five times for 26 yards on the drive, which he capped with a 7-yard run to help UW take a 7-3 lead with 4:13 left in the quarter.
Both defenses controlled the game until the Wildcats took advantage of a short field to take a 10-7 lead with 2:38 left in the half.
Northwestern took over at the UW 44 after a 33-yard punt by Lotti.
Thorson gained a yard to the 23 on fourth-and-1 on the sixth play of the drive to keep the possession alive and then capped the 12-play drive with a 1-yard pass to super back Cameron Green.
UW's offense had two more chances to score in the half but both possessions ended in failure.
Hornibrook threw his second interception of the day when safety Godwin Igwebuike outfought tight end Kyle Penniston for a 50-50 ball and the Wildcats took over at their 31 with 1:47 left in the half.
Three incompletions by Thorson took just 13 seconds off the clock and UW got the ball back at their 42 after a 17-yard punt return by Nick Nelson.
UW reached the Northwestern 42 but Hornibrook was sacked for a 3-yard loss on second down and his deep throw to Quintez Cephus was broken up by cornerback Montre Hartage.
UW finished the half with 114 yards of offense _ 66 rushing and 48 passing.
The Badgers didn't allow a point in the second half of its first three games.
That streak ended Saturday when the Wildcats added a touchdown with 4:46 remaining to close the margin to 31-17.
Northwestern recorded two first downs on its opening series of the second half but eventually punted and UW took over at its 21 with 11:15 left in the third quarter.
UW needed less than two minutes to regain the lead.
Hornibrook faked a handoff to Chris James on third-and-3 and found Cephus for 61 yards to the Northwestern 11.
Taylor scored on the next play to help UW take a 14-10 lead with 9:16 left in the quarter.
UW's defense surrendered one first down on the next series before forcing a punt and the Badgers took over at the Northwestern 38 thanks to a 12-yard return by Nick Nelson and a 15-yard penalty for unsportsmanlike conduct against Northwestern.
Hornibrook and Danny Davis hooked up for a 32-yard gain to the 6 on second down and then on second-and-goal from the 5 Hornibrook found Davis in the back of the end zone for a touchdown. Rafael Gagliaone added the extra point for a 21-10 lead with 5:26 left in the quarter.
The quarter ended that way and the numbers were startling.
Northwestern gained a modest 117 yards on 35 plays in the opening half. The Wildcats were held to 23 yards on 19 plays in the third quarter.
Meanwhile, UW's offense doubled its first-half point total _ on its first two possessions of the quarter.
The turnaround continued in the fourth quarter as UW drove from the Northwestern 43 to the 5 before the drive stalled.
No problem. Gaglianone came on to hit a 23-yard field goal for a 24-10 advantage with 11:12 left in the game.
Safety Natrell Jamerson added a 36-yard interception return for a touchdown to help UW build the lead to 31-10 with 9:54 remaining.
Northwestern's next-to-last chance ended after Thorson's final touchdown pass. The Wildcats' onside kick was smothered by UW linebacker Ryan Connelly at the Wildcats' 43 with 2:53 left.
UW could not get a first down but Jamerson downed a 33-yard punt by Lotti at the 2. The Wildcats, out of timeouts, took over with 1:09 left and 98 yards to cover.
Fittingly, UW's defense slammed the door as safety D'Cota Dixon sacked Thorson for a safety with 58 seconds left.
