Sunday afternoon in Charlottesville, Va. it was the Tigers who were the ones victims of the upset.
Clemson (20-4, 6-4) had no answer for freshman sensation Sylven Landesburg, who scored a game-high 23 points, including a game-tying, twisting layup to force overtime in an 85-81 victory.
The win broke Virginia's (8-13, 2-8) eight-game losing streak and was just the Cavs' second conference win of the year.
The Tigers jumped out to a quick three-point advantage in the extra period after Terrence Oglesby's steal and three-pointer with 4:30 left, but after that it was all Virginia thanks mostly to the smooth play of its top player, and the top freshman in the ACC.
Landesburg scored a quick six points as part of a 10-5 run on three slashing moves to the basket to give the lead back to the Cavs, and the Tigers simply had no answer on offense, committing multiple turnovers and missing a variety of shots down the stretch.
Finally, with Clemson trailing by three with under 10 seconds left, Oglesby fired a desperation three-point attempt as he tried to draw the foul, but missed. Virginia's Jamil Tucker made a free throw with six seconds left to provide the final margin of victory.
Looking back, it was the classic letdown game.
"Every game is a struggle and is a battle," head coach Oliver Purnell said afterwards. "This game in some ways was like Boston College. Virginia was giving us fits on the offensive glass and in the second half we came out and played Clemson basketball.
"But we didn't defend the ball screen well at the end of regulation or in overtime and we didn't get away with it. We missed a free throw or two then turned the ball over three of our first four possessions in overtime and that's tough to come."
Clemson started the game much like the weather outside of John Paul Jones Arena- cold. And after connecting on just 1-of-11 first-half three pointers, the Tigers found themselves on the wrong end of a 33-25 halftime score.
Trailing 5-3 early, the Cavaliers went on a 13-0 run to take an 11-point lead with just over 10 minutes remaining in the first half. Sammy Zeglinski and Jeff Jones each made three-pointers as part of Virginia's run.
Zeglinsky, who was shooting 16 percent (7-of-42) from three point range in ACC play entering Sunday's game, was perfect from the field, converting on all six of his shots and all three of his three-pointers.
Eventually Clemson's press started to take its toll, however, as the Tigers pulled within three before the end of the first half, forcing 13 turnovers.
Oglesby hit Clemson's first three-pointer of the game with 1:19 left to pull the Tigers within 29-25, but Virginia scored the last four points of the half to extend its lead to eight points.
But even then, Virginia, losers of each of its last eight games, had to know it probably wouldn't last- and it didn't.
The Tigers opened the second half on a 14-0 run, including connecting on three consecutive three-pointers to quickly build a six-point lead.
For a while, it looked like Virginia may fold, just like it had in a countless number of games this season, but it didn't.
The Cavs slowly closed the gap before going on a 10-4 run to go back up by four at 50-46.
But the Tigers had an answer once again, going on a 10-2 run of their own, including seven points scored by Demontez Stitt, to regain the lead at 58-55 with 7:44 left.
From that point on, it was back and forth.
Virginia took the lead at 72-69 after a three-point play by Mike Scott followed by a 15-foot jumper from the left wing by Landesberg with 2:46.
Then, for the 12th time of the game, the lead changed hands as K.C. Rivers converted on a fallaway 15-foot jumper 1:12 left.
Virginia's Jamil Tucker missed on a short drive down the right side of the lane on the Cavs' next possession, and after a Rivers' free throw pushed Clemson's lead to two, Virginia had one more opportunity to either win or tie
After calling timeout, Landesberg took his time at the top of the key, then calmly drove down the right side of the lane with David Potter in his face, and scored on a spinning layup to tie the game at 74.
The Tigers had three opportunities before the final buzzer sounded to end regulation, but couldn't convert from point-blank range as three different players had contested shots.
"I'm disappointed we didn't come out with guns blazing but give Virginia credit," Purnell said. "We had three or four attempts in regulation. Demontez got to the basket. Then Potter got it but we couldn't get it in. Then we played bad in overtime and that's what happens in losses."
Trevor Booker, Clemson's leading scorer entering the game, scored just four points in the second half after converting 4-of-5 field goals for 10 points in the first half.
He added two in overtime to finish with 16.
Oglesby led the Tigers in scoring with 17 on 5-of-10 shooting from three-point range.
The loss, now Clemson's fourth in league play, not only hurts the Tigers' chances of winning the ACC regular season championship, it also puts the opportunity for a first round bye in the ACC Tournament in jeopardy.
It also creates a four-team log jam for third place along with Wake Forest, Florida State and Virginia Tech.
The Tigers return to action Tuesday night against Maryland in Littlejohn Coliseum. The Terps enter the game having won three of their last four games, including a 10-point home win over Virginia Tech Saturday.
Tip-off is set for 7:30 PM.
GAME NOTES: The Cavs shot 53 percent from the field against Clemson after averaging less than 40 percent from the field in ACC play entering the game. ... Virginia retired No. 44, the jersey of former point guard Sean Singletary during halftime. ... Clemson fouled Jeff Jones on three-point shots, twice, with Jones converting a four-point play in the first half. ... The Tigers were just 1-of-11 from three-point range in the first half while Virginia made 5-of-9 from behind the arc. ... Both Clemson and Virginia had 13 turnovers apiece at halftime. ...The Tigers beat Virginia by 31 points in Charlottesville last season. ... The loss snapped a seven-game win streak in the state of Virginia for the Tigers.