"John said after the game that the important thing was that we got a win," coach Bill Carmody said. "That's the kind of kid he is."
Northwestern (16-10, 6-8) improved its postseason prospects with the victory as Dave Sobolewski scored a game-high 22 points while Drew Crawford added 11.
Julian Welch scored 21 points and Joe Coleman 12 for the Gophers (17-10, 5-9). Minnesota has lost three straight and four of its last five.
Shurna, who now has 1,902 career points, got off to a slow start and didn't get his first basket until late in the opening half. But it didn't matter, as teammates picked up the slack.
"I think we had a good all-around game," Shurna said. "(The record) is an honor, but it was more important that we defended home court against a good Minnesota team."
Before the game, Shurna got a call from McKinney offering best wishes.
"He actually called me this morning," Shurna said. "I really appreciated it. He told me just to go out there and have fun.
"He was really nice to me. He didn't have to do that, and it showed what kind of person he is."
The record-breaker came on a 3-pointer from the top of the key with 10:48 left to give the Wildcats a 50-40 lead. Shurna scored 227 points as a freshman, 619 as a sophomore and 531 last year. He has 525 through 26 starts in 2011-12.
He has scored 30 points or more three times this season and is the Big Ten's active leader with 50 games of 20 points or more.
Northwestern never trailed in the first half and established an advantage thanks in part to five early 3-pointers. Shurna started slowly with four missed shots, then erupted in the final 3:30 with Northwestern's last 12 points of the half, including a steal for a layup and two 3-pointers, as the Wildcats opened a 36-28 halftime lead.
Playing a smaller lineup, Northwestern led by as many as 14 points in the second half. Minnesota closed within 47-40 after Welch's baseline 3-pointer with 11:14 remaining.
The loss was painful for the Gophers, who saw their flickering NCAA tournament hopes diminished.
"Northwestern outplayed us and made shots," said Minnesota coach Tubby Smith. "We had a tough time attacking the 1-3-1, and the (21) turnovers did us in. But it was the defense that gave us all kind of problems."
Still, Minnesota outrebounded Northwestern 41-20, including a 17-5 edge on the offensive boards.
"When you have 21 turnovers, that neutralizes all the rebounding that you do," Smith said.
Gophers forward Ralph Sampson III had four points and now needs just 16 to hit 1,000 for his career. He would be the fifth player in Minnesota history with 1,000 points, 500 rebounds and 150 blocks.
The Gophers beat the cold-shooting Wildcats 75-52 on Jan. 22. Northwestern missed its first 14 shots in that game.
Northwestern hosts Michigan on Tuesday night, while Michigan State is at Minnesota on Wednesday.