EVANSTON, Ill. -- The backfield partnership of Connor Cook and Jeremy Langford continued to pay dividends for Michigan State on Saturday with a combined four touchdowns in a 30-6 Big Ten victory over Northwestern.
Cook had touchdown passes of 87 and 15 yards, while Langford scored on runs of 20 and 37 yards as the No. 13 Spartans (10-1, 7-0) clinched the Legends Division title and a berth in next month's Big Ten championship game.
"(We were) working all summer together, knowing what we have to do to be in the Big Ten," said Langford, a junior running back who rushed 25 times for 150 yards and has 1,110 yards this season. "Hard work pays off and that's what we've done all season."
Cook, a sophomore quarterback, completed 16-of-24 passes for a career-high 293 yards.
Spartans coach Mark Dantonio's offense has steadily improved after early season struggles.
"If you look at our offense, I think you have to look a little harder the way we're playing now," he said. "Initially, we were a defensive football team.
"Right now you can make a case in point that we can go either way, defensively or offensively."
Northwestern (4-7, 0-7) saw its faint hopes for a sixth straight bowl appearance extinguished with a seventh straight loss. Quarterback Trevor Siemian was 25-of-43 for 227 yards, but Northwestern managed only 80 rushing yards.
Yet another injury hampered the Wildcats in the first quarter, when Spartan strong safety Isaiah Lewis knocked Northwestern quarterback Kain Colter out of the game with a hit.
Lewis, in turn, was ejected for targeting after Colter caught a pass from Trevor Siemian. Colter walked off the field holding an arm against his body, but his specific condition was unknown.
"I wish we had the health that we had a year ago," Wildcats coach Pat Fitzgerald said. "We were really a fortunate team a year ago in these close games and we were able to win because we had all the weaponry in all three phases. Not to have it (this season) hurts."
Following Colter's hit, the Wildcats drove to the Spartan five-yard-line but stalled and settled for Jeff Budzien's 22-yard field goal.
Michigan State took a 7-3 lead on Langford's 20-yard touchdown run with 8:22 showing in the second.
The Spartans made it 14-3 on an 87-yard pass play from Cook to wide receiver Bernie Fowler with 4:31 let in the half. Fowler made a one-handed grab over the back of Wildcat cornerback Matthew Harris and sprinted the remaining 35 yards untouched.
Northwestern replied with another drive inside the Michigan State 10 thanks to a 39-yard pass from Siemian to super back Dan Vitale that set up the Wildcats at the Spartan eight.
The Wildcats reached the Spartans three before Budzien was called in on fourth down to kick a 20-yard field goal that trimmed the deficit to 14-6.
Michigan State opened the second half with Cook's 48-yard pass play to Tony Lippett to the Northwestern 24. But the Wildcats stiffened and wouldn't allow the Spartans past the 15, leading to a 37-yard field goal by Michael Geiger and a 17-6 lead with 11:33 left.
Cook's second touchdown strike came with five minutes left in the third, a 15-yard pass to tight end Josiah Price in the end zone. Geiger's extra point kick was blocked by tackle Chance Carter, leaving the Spartans ahead, 23-6.
Kurtis Drummond's fourth quarter interception of a short Siemian pass at the Northwestern 37 set up Michigan State's next touchdown. On first down, Langford picked up his second score on a 37-yard run.
Langford was handed a Legends Division champion's hat after the game but hopes he won't have it for long.
"I love the hat," he said. "I hope to switch it out (for a Big Ten championship hat) in a couple of weeks."
Michigan State, which would play either Ohio State or Wisconsin in the Dec. 7 championship game at Indianapolis' Lucas Oil Stadium, entertains Minnesota in next Saturday's season finale.
Northwestern travels to Illinois.
"This year 13 is over in a week and good riddance," Fitzgerald said.
NOTES: Michigan State entered the game leading the nation in total defense for the 10th straight week. The Spartans had allowed an average 228.4 yards per game and only 57.3 yards rushing. ... Michigan State clinched its last Legends Division title in 2011 with a 31-17 victory at Northwestern and have beaten the Wildcats five straight times in Evanston. ... The Spartans lead the overall series 37-17 and 19-10 in Evanston. ... Five of Northwestern's seven Big Ten losses have been by 10 points or fewer. ... Jeff Budzien's field goals gave him a school record 267 career points. Brian Gowins (1995-98) held the previous record of 262. ... Fourteen Wildcats played in their final game at Ryan Field on Saturday. Since arriving in 2008, the five-year class has contributed to 35 wins and four straight bowl appearances.