Diakite, who along with fellow senior Braxton Key was playing in his final game at John Paul Jones Arena, made one of two free throws with 1:48 left to put Virginia ahead to stay at 52-51. Center Jay Huff blocked Steven Enoch's short jumper with 51 seconds to play and secured the loose ball.
Moments later, Kihei Clark's three-pointer provided a 55-51 lead, and Diakite's two foul shots all but sealed Virginia's eighth straight senior day triumph. A three-pointer by Louisville with less than a second remaining made it the Cavaliers' fourth consecutive win by three points or fewer and the seventh in their past eight games.
"I don't think that was our best basketball yet, but it was a really good game," said Clark, who led the Cavaliers with 18 points and five assists and grabbed five rebounds. "We needed this. We are going to keep evolving no matter what. Like I said, the job is not done."
Virginia (23-7, 15-5) entered with an outside chance of sharing the regular season ACC title but needed first-place Florida State to lose to Boston College. The Seminoles instead won handily, 80-62, leaving Virginia, already assured of a double bye in next week's ACC tournament, in a three-way tie for second.
A split in the regular season series with the Cardinals (24-7, 15-5) appeared certain to unfold until Virginia’s 14-point advantage vanished when Darius Perry made a three-pointer to knot the score at 51 with 5:12 left, capping a 19-6 burst during which Jordan Nwora had 10 consecutive points.
The lead had swelled to 43-29 with 13:20 left on a three-pointer by Tomas Woldetensae, whose proficiency from beyond the arc helped buoy the Cavaliers following three consecutive losses in the first half of January that dropped them to .500 in the conference.
The resurgence then commenced with Virginia outlasting Wake Forest in overtime, 65-63, and continuing to squeak out victories by slim margins during its ascent in the ACC standings, beating such powerhouses as Florida State, ranked fifth at the time, and then-No. 7 Duke each by two possessions or fewer.
The Cavaliers’ only loss in the past 11 games heading into Saturday came against Louisville, 80-73, at KFC Yum! Center.
“I treated it just like the rest of the games,” Diakite, a redshirt senior from Guinea, said of his final home game. “I knew our job was not done yet. We had to come in against a big caliber team and get it done. I remember the last time we played them, we did not execute very well.”
Key and Diakite figured prominently Saturday during a rally late in the first half after the reigning national champions had trailed by seven in front of an announced crowd of 14,629.
A 12-2 surge started with Key’s midrange jumper, and Diakite’s jumper tied the score at 22 before Clark swished a three-pointer from the left wing for Virginia’s first lead since 6-5 in the opening minutes.
Clark scored seven of Virginia’s final nine points of the first half for a 31-24 lead going in to a locker room. He also hit two technical free throws when Louisville Coach Chris Mack was assessed a technical for protesting a lane violation called on the Cardinals while Huff was attempting to complete a three-point play.
“That is the best send-off we can give them, especially with a team like Louisville,” Huff said of Diakite and Key. “We really wanted to win to honor them and what they have done for the program.”
Both players were recognized in a pregame ceremony, each having authored a signature moment during last season’s run to the national championship, starting with Diakite improbably sinking a long jumper at the buzzer to force overtime against Purdue on the way to an 80-75 triumph in the regional finals.
In the national championship game, Key blocked Jarrett Culver’s jumper at the regulation buzzer with the scored tied against Texas Tech. The Cavaliers went on for an 85-77 win in overtime in Minneapolis for the program’s first NCAA title one season after ignominiously becoming the first No. 1 seed to lose to a 16.
“I kind of thanked them for what they’ve meant to the program yesterday before practice and after practice,” Cavaliers Coach Tony Bennett said. “I said, ‘As much as I’d love it if [Boston College] could get it and you can get a share of the ACC title, that doesn’t take away from what just transpired in terms of the effort you put out here.’ ”