CHAMPAIGN, Ill. -- Since becoming a father for the first time on Thursday, Illinois guard Kendrick Nunn isn't sleeping as easily.

However, he and the Fighting Illini probably made their restless fan base sleep a bit easier after a dominant second half Sunday fueled an 84-70 Big Ten Conference upset of No. 20 Purdue at State Farm Center.

Scoring 18 of his 22 points after halftime, including nine in a 70-second stretch to personally break a 37-37 deadlock, Nunn lifted Illinois (9-8, 1-3) to its first conference win.

"It's been a wild week for me," Nunn said. "I'm proud of my son's birth, and I'm glad we came out here and got the win."

Nunn put the Illini in control with a 3-pointer, an uncontested driving layup and a four-point play that gave them a 46-37 advantage with 18:23 to play, firing up a crowd of 12,246.

Later, Nunn, who is 6-foot-3, added an emphatic dunk over 6-9 forward Caleb Swanigan and then tossed in a 3-pointer from just in front of coach John Groce for a 71-56 advantage with 4:21 left, basically ending the game's competitive phase.

With Nunn heating up and 6-6 junior guard Malcolm Hill going off for 17 of his game-high 30 points after halftime, Illinois outscored Purdue (14-3, 2-2) with just its 1-2 punch in the final 20 minutes.

"That start of the second half was probably the difference in the game," Boilermakers coach Matt Painter said. "For (Illinois) to be successful, both of those guys have to have it going at the same time, and obviously, they did."

The Illini shot a season-best 54.2 percent from the field, canning nine of 17 3-point attempts, while hitting 23 of 28 at the foul line and committing just 10 turnovers.

It was a far cry from their previous outing, an embarrassing 79-54 loss Thursday night at a Michigan State side playing without national Player of the Year candidate Denzel Valentine. Groce decried his team's toughness and effort following that game, then spent the next two days pounding his point home at practice.

"I'm not going to sugarcoat it," Hill said. "Practices were just hell."

Playing with the bounce that a team with any pride should possess after a humiliating result, Illinois took the lead early in the first half and let go only briefly just before intermission.

Although they often played with just one player taller than 6-6 against a team owning a front line averaging nearly 6-10, the Illini consistently created good looks while preventing Purdue from exploiting its considerable height advantage.

Switching defenses and doubling the post from multiple places, Illinois forced 16 turnovers and converted those into 24 points.

"You look at our losses and the turnovers are there, and when we win, they're not there," Painter said. "So it's not hard to figure out."

Swanigan and reserve guard P.J. Thompson scored 12 points each for the Boilermakers, while center A.J. Hammons added 10.

Reserve guard Jalen Coleman-Lands scored 10 for the Illini.

"I don't want this to be a one-time thing in a game or in practice," Groce said of his team's performance. "I want this to be more like the standard. We wanted to play unselfishly, play with toughness and execute."

NOTES: Illinois C Mike Thorne and F LeRon Black remain on the shelf with knee injuries and there is no timetable for their return. ... Purdue entered the game ranked first in adjusted defensive efficiency, according to Kenpom.com, at 87.2. The Boilermakers also led Division I in defensive field goal percentage at 35 percent. ... Fighting Illini G Jalen Coleman-Lands was replaced in the starting lineup because of a "minor violation of team rules," according to coach John Groce. G Aaron Jordan got the start and scored four points.