One week ago, Purdue and Wisconsin jumped to the head of the class in the Big Ten power rankings, leapfrogging the two Michigan schools that had commanded the top spots for most of the season.

At the time, both the Boilermakers and Badgers were riding significant winning streaks and creating their fair share of good breaks along the way.

Then the Badgers tested themselves against Michigan and Michigan State and walked away with consecutive losses. Meanwhile, Purdue forgot to unpack its offense for the second half in a disheartening road loss to Maryland.

Elsewhere in the Big Ten, Indiana keeps losing, Ohio State and Illinois each has won three straight and only three games separate the bottom six teams in the conference. The Big Ten isn’t going to get 10 teams in the NCAA Tournament, as has been widely speculated, but the depth of the league continues to impress.

* Big risers: It’s back to the top of the rankings for Michigan State. After losing three straight — as well as linchpin Joshua Langford for the season — the Spartans have rallied in a big way with convincing wins at home against Minnesota and at Wisconsin.

* Big fallers: Welcome to the basement, Nebraska. Now carrying a seven-game losing streak, there seems to be no end in sight for the misery the Cornhuskers are experiencing. Coach Tim Miles had to choke back tears during his postgame news conference after a 15-point home loss to Maryland.

* Big picture: Several teams have pushing Michigan and Michigan State near the top of the Big Ten standings, and that doesn’t figure to completely go away anytime soon, but the Spartans and Wolverines still have to play each other twice. The conference title may come down to those two games.

Here are this week’s rankings (records through Tuesday's games):

1. Michigan State (20-5, 11-3): The Spartans beat a pair of NCAA Tournament teams (Minnesota and Wisconsin) by an average of 11 points. (Last week: 5)

2. Michigan (22-3, 11-3): John Beilein was ejected for the first time since 1979, so he didn’t have to see the Wolverines take a loss at Penn State. (LW: 3)

3. Iowa (19-5, 8-5): It took a significant comeback to beat Northwestern, yes, but these Hawkeyes look like a team you don’t want to face in the postseason. (LW: 4)

4. Maryland (19-6, 10-4): The Terrapins outscored Purdue 40-18 in the second half on Tuesday to win in convincing fashion. (LW: 6)

5. Purdue (17-7, 10-3): It was only one half of bad basketball, but that closing stretch at Maryland was troubling. (LW: 1)

6. Wisconsin (17-8, 9-5): Despite an 0-2 week, Ethan Happ became the fourth Big Ten player to top 2,000 career points and 1,000 rebounds. (LW: 2)

7. Ohio State (16-7, 6-6): The Buckeyes are 0-5 against Big Ten teams ranked higher than them in the KenPom.com national rankings. (LW: 8)

8. Minnesota (16-8, 6-7): The Gophers are firmly rooted in the middle of the league after a non-competitive, 24-point loss at Michigan State. (LW: 7)

9. Illinois (9-15, 5-8): Three straight wins for the Illini shows that something is starting to click. (LW: 10)

10. Penn State (9-15, 2-11): A challenging season for the Nittany Lions got some payoff with a rush-the-court win against Michigan. (LW: 13)

11. Indiana (13-11, 4-9): The Hoosiers are 1-9 since Jan. 3 and have lost four straight home games for the first time in eight years. (LW: 9)

12. Rutgers (11-12, 4-9): It’s hard to say what was more surprising, that the Scarlet Knights scored 94 points against Illinois, or that they still lost. (LW: 11)

13. Northwestern (12-11, 3-9): The losing streak hit four games when the Wildcats blew a late 13-point lead to Iowa. (LW: 14)

14. Nebraska (13-11, 3-10): It just keeps getting uglier in Lincoln, where the Cornhuskers have lost four straight. (LW: 12)

ajardy@dispatch.com

@AdamJardy