EVANSTON, Illinois (Ticker) -- Luther Head guided top-ranked Illinois into uncharted territory.
Head scored a season-high 26 points as Illinois improved to 18-0 for the first time in its 100-year history with a 78-66 victory over Big Ten Conference rival Northwestern.
Head made 9-of-13 shots for the Illini, who became the first Big Ten team to win its first 18 games since the 1986-87 Iowa squad, which finished 30-5.
The Illini had started 17-0 during the 1988-89 season, when they went to the Final Four.
"We got to keep taking care of ourselves," Illinois coach Bruce Weber said. "We need to worry about winning."
Roger Powell Jr. added 15 points and Dee Brown 12 for Illinois, which improved to 4-0 in Big Ten play and beat Northwestern for the 10th time in 11 meetings.
Illinois held just a 53-48 lead before James Augustine made a layup and free throw with 11:54 left to trigger a 25-12 run. Head scored 12 points during the burst, which he capped with a 3-pointer with 3 1/2 minutes left.
"You have to play very well to beat a team of that caliber, and we did not," Wildcats coach Bill Carmody said.
Vedran Vukusic scored 20 points to pace Northwestern (8-8, 1-3), which lost despite shooting 57 percent (24-of-42).
Davor Duvancic added 13 points and T.J. Parker 12 for the Wildcats, who trailed at the half, 42-34.
The Wildcats committed 16 turnovers, which the Illini converted into 20 points. Northwestern scored 11 points off just eight Illinois giveaways.
"We have played three games in a row now where we shot over 50 percent and we have not won any of them," Carmody said. "It is turnovers. They are just stacking up on us."
Last year, Northwestern beat Illinois here, 70-60, but the Wildcats were unable to post back-to-back home wins in the series for the first time since 1974 and 1975.
"It was similar to last year. The difference was we are a year older, we know how to win on the road," Weber said. "Last year we went in too comfortable. This year it was a different story, we know what it's all about."