Brennan finished with 403 yards and three touchdowns on 33 of 53 passing.
He pulled a rabbit out of his hat on several occasions, dazzling with his ability to escape perilous situations and make a big play.
And yet when the dust settled it looked like Wisconsin had contained the Warriors' sophomore signal-caller.
Giving up more than 400 passing yards is far from ideal, but the Badgers made plenty of big plays of their own to keep Brennan from dominating the game. Wisconsin kept him scrambling frequently and sacked him five times. And Brennan turned the ball over twice in the second half, leading to 10 Wisconsin points.
Early in the game Brennan had the Badgers' defensive line gasping for air. On one play he appeared to be hemmed in near the left sideline. But he spun away from pressure then ran backwards to avoid one defender before running all the way across the field and finding receiver Ryan Grice-Mullen for 12 yards to the Badger 26.
Hawaii scored its first touchdown two plays later.
"He's much more mobile than I anticipated," UW head coach Barry Alvarez said. "He made our guys work very hard. Had a hard time, particularly in the first half—thought that we did a better job in the second half containing him and putting pressure on him."
Brennan's fleet feet got him into trouble, however. Brennan fumbled as he tried to evade pressure early in the third quarter. Wisconsin recovered the fumble but was held to a field goal on the ensuing possession, despite starting with the ball at Hawaii's 8.
In second quarter, Brennan was sacked as he tried to scramble to his right. Rather than throwing the ball away he took an 11-yard loss when linebacker Dontez Sanders caught up with him. That led to a 46-yard field goal attempt that could have been far easier. Dan Kelly missed wide left and Wisconsin maintained a 17-7 edge.
"He's a real agile quarterback and it is real tough to get him down but fortunately on several occasions we did get to him and get him down," linebacker Mark Zalewski said. "He was agile and he made a lot of plays on the run but when we needed to get off the field we did."
Sanders, who finished with a career high two-and-a-half sacks, made the biggest defensive play of the game when he intercepted a Brennan pass at midfield on the first play of the fourth quarter.
That led to a 10-play 41-yard drive that gobbled up nearly six minutes and finished with the Badgers up 41-17.
"It was huge. It's third-and-short and we kind of expected certain plays," Zalewski said. "… And Dontez did a great job anticipating that, getting a hand on the ball and then setting the offense for another score."
From time-to-time UW used a spy on Brennan, with Sanders frequently filling that role. The Badgers also blitzed more in the second half and had some success getting to Brennan or, at a minimum, making him less comfortable in the pocket. Hawaii's first touchdown of the second half, however, did come versus a blitz.
"We were able to bring some pressure and then we showed pressure and bailed out and played some different coverages and that helped us as well," defensive coordinator Bret Bielema said.
The Badgers tried a wide range of defensive setups in the first half, using their base 4-3 defense, a regular 4-2-5 nickel, a "42" nickel with four cornerbacks, a "33" with three corners and a "33" with four corners.
As the game progressed, however, UW settled in with a 4-2-5, three-cornerback look.
"We knew when we were up by two touchdowns that they were going to start pressing the issue," Bielema said. "We felt that sometimes when that happens in zone, when we had our base defense, (Brennan) can scramble around back there and find something down the field.
"What we're trying to do is stay in man free, have somebody protecting over the top, have a linebacker spy on the quarterback, try to make them earn every yard they got."
It was not a stunning performance. The Badgers' tackling was sloppy in the first quarter, particularly on Nate Ilaoa's 19-yard run and 23-yard reception during Hawaii's first touchdown drive.
But the Badgers bounced back often and held Hawaii to just 17 points before a touchdown in the closing minute when the game was well in hand.
"There's a lot of things we have to correct," Zalewski said. "We let up quite a few yards, quite a few first downs, but we kept them off the scoreboard… In terms of the score we did all right, but just too much yardage."