Buckeyes forward Keita Bates-Diop fights for the putback and scores with 2.8 seconds left to lift Ohio State over the Boilermakers 64-63. (1:36)

WEST LAFAYETTE, Ind. -- Ohio State coach Chris Holtmann said his mind was full of doubts at Purdue's Mackey Arena on Wednesday night as he watched the final possession of the biggest game of his young Buckeyes tenure play out in front of the most raucous crowd he can remember.

Ohio State trailed by a point with 16 seconds left when fifth-year senior Andrew Dakich corralled an offensive rebound. Holtmann called timeout.

The plan was to get the ball to Big Ten player of the year candidate Keita Bates-Diop. Purdue's relentless defense wouldn't allow it. A ball screen failed to shake the Buckeyes' leading scorer loose, so Jae'Sean Tate drove to the basket instead.

Richard Bates, sitting a few rows deep in the deafening Mackey crowd, knew his son would find a way to get involved and make a play. It's what he has seen Keita do since the second grade, Bates said afterward.

Holtmann hasn't been around that long. He wasn't so sure.

"I had plenty of doubts," Holtmann said as he jogged off the court smiling after celebrating the 64-63 victory Bates-Diop secured by finding a way to make a play in the final seconds. "Maybe I need to start trusting him."

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Tate's layup missed. Bates-Diop followed close behind and tipped in a putback to give No. 14 Ohio State a dramatic win on the road against No. 3 Purdue. The Buckeyes (21-5 overall, 12-1 Big Ten) tied Purdue's record in conference play as the Big Ten heads down its home stretch. With five games left on the schedule and only one of them against a ranked opponent, the Buckeyes are in the driver's seat to win a regular-season title in Holtmann's first season in Columbus.

It isn't hard to understand why Holtmann wasn't sure how that final possession would play out. Ohio State looked shaky at times against a deep and dangerous Purdue team. There are questions this team still has to answer before it can be considered a reliable threat in the conference tournament and beyond.

Holtmann's frontcourt did not have much of an answer in the post for 7-foot-2 Purdue battering ram Isaac Haas in the first half. In the second half, a handful of panicked possessions allowed Boilermakers guard Carsen Edwards to catch fire and pry open a 14-point lead with just over 10 minutes to play.

"He's a load," Holtmann said of Edwards. "I thought we had some out-of-character offensive possessions. I think what we needed to do was settle down and trust each other a little bit more."

Holtmann said learning to trust one another will be a teaching point in film this week -- one that he's fairly confident his group will need again if it's going to keep climbing in a positive direction. It's a lesson he's still learning as well.

Bates-Diop, who had a team-high 18 points, started to settle things down with his first putback basket of the night midway through the second half. He scored eight of his points in those last 10 minutes, including the game-winning bucket with three seconds left. In between, he got help from Tate, Musa Jallow and Andre Wesson, who banked in a 3-pointer to give Ohio State its first lead of the second half with 1:16 left to play.

"I tried to [call glass]," Wesson joked afterward. "When it left my hand, at the last second, I thought about it."

Jallow and Wesson combined for 23 points, including six 3-pointers between them. That was an unexpected boost for a team that had to find new options on offense without suspended senior guard Kam Williams. Their response was another reason for Holtmann and his players to start believing a bit more in one another.

The Buckeyes, for all their ahead-of-schedule success this season, had defeated only one ranked opponent before Wednesday's road upset. Now they have victories over No. 3 Purdue and then-No. 1 Michigan State to go with a December win over No. 20 Michigan, which was unranked when it lost to the Buckeyes.

Purdue and Michigan State, based on the depth of talent alone, are still likely to be favored if they run into Ohio State again in the postseason. Any slip in their remaining regular-season games, which include a trip to Michigan next week, could temporarily derail what is shaping up to be a special season for Ohio State.

In that light, it's easy to understand why Holtmann remains a bit uneasy about singing his team's praises or blindly believing in his breakout superstar.

Ohio State is playing solid defense, though, and it boasts the most consistently exciting player in the Big Ten in Bates-Diop. Maybe Holtmann's grinning postgame faith in Bates-Diop is well-placed. Maybe the Buckeyes should start trusting one another to get the job done. And maybe it's time for the rest of college basketball to start trusting them too.