Four nights later, the sophomore guard hit on 8 of 10 three-point attempts but could not carry the Buckeyes to a victory against the Wildcats. A three-pointer by Northwestern's John Shurna with 3.3 seconds remaining handed his team a 72-69 victory that dropped the Buckeyes to fifth place in the Big Ten.
While it was Diebler's offense that stole the show, it was his defense that nearly clinched the game at the end for the Buckeyes. With OSU trailing 69-67 in the final minute of play, Diebler came up with a steal near midcourt that he turned into a fast-break layup that knotted the score with 26 seconds remaining.
At the other end of the court, Northwestern worked the ball around and got it down low to Kyle Rowley. His shot attempt was blocked by Diebler, and the ensuing loose ball went out of bounds near midcourt with Northwestern retaining possession with 8.4 seconds left.
From there, Michael Thompson brought the ball up the right side of the court and drove the lane just enough to draw OSU's William Buford a step away from Shurna. Thompson then found Shurna, who buried the three in front of his team's bench with Buford closing.
The Buckeyes (17-7, 7-6 Big Ten) had one more chance to tie the game but could not get a shot off. Needing to push the ball the entire length of the court, junior point guard Jeremie Simmons pushed the ball up the left side of the court and found Diebler with a wild pass that he was unable to control in time to get a shot off.
With that, the crowd at Welsh-Ryan Arena celebrated the end of both a three-game losing streak and a 17-game OSU winning streak at the hands of the Wildcats.
"Big-time shot by that guy," OSU head coach Thad Matta told the Ohio State Basketball Radio Network. "We didn't have what we needed mentally defensively tonight. Hard to explain. It's unfortunate because I felt like we shot the ball well in the second half and we defensively just didn't get the job done in finding the guys."
Diebler finished with a career-high 28 points, and his eight three-pointers tied him for the second-most in a single game in program history.
"Before the game I said, ‘Jon you're going to have some great looks tonight. You're not going to have to take any bad ones tonight,' " Matta said. "Jon showed some great patience and did a great job of getting the shots up there and played a heck of a game."
He was outdone by a pair of Wildcats in Kevin Coble and Craig Moore, who combined for 49 points on 18-of-30 shooting. Coble's 26 points were aided by a 4-of-6 performance from beyond the arc, while Moore was 7 of 12 from deep en route to finishing with 23 points.
Less than three minutes into the second half, it looked like the Buckeyes had the game well in hand. A Diebler three-pointer pushed their lead to a game-high 12 points at 40-28, and the game appeared to be slipping away for the Wildcats.
But on the next possession, Rowley converted a three-point play to cut the deficit to nine points. His basket sparked what would become a 21-3 Northwestern run that put the home team ahead by six, 49-43, with 10:22 remaining.
OSU's leading scorer for the season in Evan Turner was a non-factor for much of the game, finishing with 14 points and six assists but committing eight turnovers. Mullens added 11 points, but freshman William Buford had just three points on a basket that came with 57.6 seconds left that pulled OSU to within two points at 69-67.
As a team, the Buckeyes committed 15 turnovers that the Wildcats turned into 16 points.
Both teams opened the game hot from the floor. When Moore connected from deep to make the score 15-14 in favor of the Buckeyes, it made his team 4 for 4 from behind the arc.
One possession later, Diebler buried his fourth trey on as many attempts to push the OSU lead to four points.
Both teams went into the half with OSU holding the largest lead of the half at nine points. After Coble beat Mullens along the baseline for a basket that made it 25-23 Buckeyes with 5:09 remaining, the visitors then closed the half on a 12-5 run thanks to Mullens and Turner who had six points each.
Turner had the biggest basket during the run, corralling a loose ball in the paint after Diebler's lone miss from deep in the first half and scoring while drawing the foul. His subsequent free throw set the halftime score.
Diebler was the lone offensive spark in the early going for the Buckeyes, scoring 15 of the team's first 21 points. Two three-pointers bookended an OSU scoring drought that lasted 3:23 and saw Matta call timeout to yell at his players after a Northwestern basket.
With OSU clinging to an 18-17 lead, Moore caught the ball along the left wing and promptly cut to the heart of OSU's 3-2 match-up zone defense. As William Buford made a vain attempt to swipe at the cutting opponent, Moore converted an acrobatic basket that banked off the glass and fell to give his team a 19-18 lead.
A red-faced Matta immediately called timeout and laced into his players, but it would take three more possessions until Diebler's fifth three-pointer of the half helped OSU regain the lead.