Shaking off some would-be tacklers and outrunning others, the powerful 6-foot-5 wide receiver had 200 yards and three touchdowns on only 10 catches, his second consecutive monster game, and simply overwhelmed the overmatched Wildcats.
"If you would have listened to me in July, I told everybody that guy would be one of the top receivers in the country if he had not gotten hurt," Missouri coach Gary Pinkel said. "The neat thing about Danario is he is a great team player, a great kid."
Alexander, whose career has been marred by four surgeries, had 214 yards receiving the week before against Baylor.
"I had to try to come out and be the best leader I could be, just try to carry the team," he said. "You've got to stay positive. You can't ever get down on yourself. If you stay positive, good things will happen to you."
Blaine Gabbert was 20 for 27 for 298 yards and three TDs for the Tigers (6-4, 2-4 Big 12), who had lost four of five and dropped out of contention for their third straight North championship.
Kansas State (6-5, 4-3) started the day with a half-game lead over Nebraska in the North Division. The Huskers will host the Wildcats on Saturday in what could be the division's decisive showdown. It will be the final regular-season game for Kansas State, while Nebraska will have one game after that.
"We didn't play like Big 12 North champions today, but we still have an opportunity to do that next week," quarterback Grant Gregory said. "It's nice to know that."
Alexander hooked up with Gabbert on scoring plays of 54, 16 and 80 yards.
"When you get him the football, he makes tremendous plays with it," Gabbert said. "You saw his playmaking ability again today."
Missouri had not scored a touchdown in the second half of any of its five conference games this year, but Alexander changed that with his 80-yard scoring play in the final seconds of the third quarter. Making the reception near midfield, he juked one would-be tackler and then with long, powerful strides outran two more into the corner of the end zone.
"He's unbelievable," said Kansas State linebacker John Houlik.
Missouri wrapped up its fourth straight victory over the Wildcats with touchdown runs in the fourth quarter of 4 and 13 yards by Derrick Washington, each after a Kansas State turnover.
Next weekend's date with Nebraska will be the most meaningful late-season game Kansas State has played since coach Bill Snyder's teams were contending nearly a half-dozen years ago, before he went on what turned out to be a three-year retirement.
"I told our team that they are the luckiest bunch of guys in the Big 12, to go out and get it handed to you like we did today and still have the opportunity to win a North Division title and possibly play in a bowl game," said Snyder. "Most teams can't play and coach the way we did today and still control their own destiny."
The victory made the Tigers bowl-eligible for a school-record fifth straight year. Since two of Kansas State's wins were against lower-division teams, they need to win at Nebraska to be bowl-eligible.
Josh Cherry kicked four field goals to account for all the scoring for Kansas State, which failed to score a touchdown for the first time all year. It was also the only home loss for the Wildcats this season.
Cherry's field goals went for 47, 34, 35 and 33 yards. He was 4 for 4.
Missouri's tough run defense held Daniel Thomas, the Big 12's leading rusher, to 79 yards on 23 carries.
Even when the Wildcats hit Alexander so hard they knocked the helmet off his head, they could not get a break. A vicious tackle on a third-down catch in the fourth quarter separated Alexander from both the ball and the helmet, and Kansas State recovered what it thought was a turnover.
But the rule states that as soon as a player's helmet comes off, the play is dead. So the Tigers retained possession and went ahead 31-12 a few minutes later on Washington's 4-yard run.
"He was sitting there taking all those shots - his helmet flipped up one time," said Pinkel. "He got hit in the head twice. What a great example for your football team."