The junior guard and Big Ten's leading scorer was quiet in the first half but came alive at just the right time for the 11th-ranked Buckeyes (16-1, 3-1).
With a little more than eight minutes left in the game, Hill made a three-pointer from the right wing to stretch a 55-54 lead to four points and kick off a 12-1 run. She had eight points along the way, including two fast-break layups that came off of steals.
"She's not someone to mess around with the ball in front of," Ohio State head coach Jim Foster said.
Sophomore forward Darryce Moore capped the run with a layup at the 6:19 mark to give the Buckeyes a 67-55 lead.
Northwestern head coach Joe McKeown's team did not fold at that time, but the Wildcats (11-6, 1-3) would not get closer than five the rest of the way. That came thanks to a Morgan Jones three-pointer that made it 72-67 with 2:01 to go, and the Buckeyes had an answer.
Ohio State ran the shot clock down to single digits before Samantha Prahalis penetrated the Northwestern zone and kicked the ball out to a wide open Amber Stokes, who stroked a lefty three-point jumper from deep in the corner to the delight of 3,188 fans at Value City Arena.
"It was just like an iso play for me," Prahalis said. "The back line stepped up and I saw she was open so I just passed it to her and she hit it."
After Karly Roser hit a pair of free throws for Northwestern, Hill buried a trey from the left wing to take the last of the wind out of the Wilcats' sails with 43 seconds to go.
"I thought defensively we broke down at the wrong times," McKeown said. "Ohio State made us pay. We kept making plays to get back in the game, but we could never get the lead in the second half."
Hill's shot came on Prahalis' sixth and final assist of the night. The senior point guard also scored 20 points, 14 of which came in the first half while Hill was tallying only five.
"They're as good as backcourt as you're probably going to see, not just in the Big Ten but in college basketball," McKeown said. "They have the freedom and the green light so they play like little kids on the playground. Swagger is maybe the word."
There were many contributors for the Buckeyes, who were coming off their first loss of the season at Michigan four days earlier.
Stokes, a 5-11 guard, finished with 11 points and added four offensive rebounds as well as three steals in 27 minutes while forwards Moore, Aleksandra Dobranic, Martina Ellerbe and Emilee Harmon all had quality stretches of playing time off Foster's bench.
Hill made 6 of 10 shots in the second half after going only 2 for 8 in the opening 20 minutes. She never looked frustrated early, however.
"Good players do that, they figure it out, and they don't let things stay in their head," Foster said. "They think the next shot is going in."
Center Dannielle Diamant led Northwestern with 23 points while Kendall Hackney, a former Ohio Ms. Basketball in high school, tallied 15 and Jones finished with 11. Guard Tailor Jones added 10 off the bench.
Ohio State turned 17 Northwestern turnovers into 30 points.