MADISON, Wis. (AP) -- Dick Bennett wondered why Mark Vershaw hadn't taken any 3-pointers this season.

Now the Wisconsin coach knows: Vershaw was just waiting for the right time.

	Wisconsin's Maurice Linton, left, hugs teammate Mark Vershaw on Saturday after the Badgers upset visiting Illinois.

Vershaw made his first 3-pointer of the season with 17 seconds left in Wisconsin's 63-59 upset of Illinois (No. 17 ESPN/USA Today, No. 19 AP) on Saturday.

"I knew if I missed it I'd hear about it, because it's not a normal shot for me," Vershaw said. "So I figured I had better make it."

On Friday, Bennett saw Vershaw taking that exact shot in practice.

"I said to Mark, 'Why don't you ever shoot that shot?'" Bennett said. "He didn't respond, as usual."

Vershaw's unlikely game-winner was the high point of a frenzied second half in which Wisconsin erased a 15-point halftime deficit, the team's biggest comeback under Bennett.

Illinois' Marcus Griffin had a chance to tie the game with 3.6 seconds left, but he missed two free throws.

"You'd like to be able to hang on and finish, but Wisconsin made the shots and we couldn't," Illinois coach Lon Kruger said.

The Badgers upset a ranked opponent at the Kohl Center for the third time this season. Illinois took a 33-18 lead into halftime, but the outside shooting of Duany Duany and Wisconsin's defensive pressure melted the Illini.

"We all got it going in the second half," Duany said. "We just rolled."

Wisconsin (9-5, 1-1 Big Ten), which lost its conference opener at Indiana on Wednesday, beat Texas and Temple in Madison earlier this year. Illinois (9-4, 1-1) lost for just the second time in nine games.

Vershaw scored the Badgers' final seven points of the game, while Duany scored 12 of his 15 points on four 3-pointers in the second half. Cory Bradford led the Illini with 14.

Illinois was 2-for-19 on 3-pointers, a problem that was largely the result of Wisconsin's defense.

"It was a learning experience for me to play against this defense," said Griffin, who was held to nine points. "I've never seen double-teams like that. They really came at me."

Jon Bryant made a 3-pointer with 4:38 left that gave Wisconsin its first lead since the game's opening minute at 51-50, and Duany hit another trey that put the Badgers up 56-53 with 2:28 left.

After Vershaw made two free throws, Bradford hit a 3-pointer and freshman Frank Williams, who beat Ohio State (No. 18 ESPN/USA Today, No. 13 AP) with a 3-pointer at the buzzer in the Illini's last game, converted a three-point play to put Illinois up 59-58 with 32 seconds left.

The Illini then left Vershaw alone, and the gangly 6-foot-9 forward drilled a 3-pointer from straightaway. Vershaw had two opportunities to shoot 3-pointers earlier in the game, but he passed.

"They're not going to really pressure me out there, so I just decided I'm not going to hesitate again," Vershaw said. "I was in rhythm."

The shot was even sweeter for Vershaw because it came against a team featuring several players he battled as a high-schooler in Illinois.

Illinois missed three shots on the next possession, but Griffin was fouled. Before he shot his free throws, Kruger requested an instant-replay review of Vershaw's shot.

A new rule allows coaches to review last-minute 3-pointers to make sure the shot was taken behind the line. Referee Ed Hightower let the basket stand.

With the Kohl Center crowd of 17,142 screaming in his face, Griffin clanged the first free throw. He intentionally missed the second, but Vershaw rebounded and hit two free throws. Bradford missed a 3-pointer at the buzzer.

Bennett confronted the officials at halftime after a series of iffy calls went against the Badgers. But the referees didn't have much to do with Wisconsin's 23 percent shooting -- including 1-for-14 on 3-pointers -- in the first half.

"I didn't rant or rave," Bennett said of his halftime speech to his team. "I just said I'm embarrassed, and we're disgraceful."

"He said if we go out and play another half like that, we don't belong here," said Wisconsin's Mike Kelley. "He's a good motivator like that."

The Badgers opened the second half with a 17-4 run, keyed by two 3-pointers by Duany. Wisconsin pulled to 47-46 when defensive standout Kelley stripped the ball from Bradford and drove the length of the court for a layup with 8:04 to play.