His team turned away the Huskies three times on the game's final possession and came away with a 58-57 win on Thursday night.
''We knew they can't win if they couldn't score,'' Clark said. ''It came down to making stops. We weren't scoring, but we were holding them from scoring.''
Clark's 3-point play on offense with 12 seconds left provided the winning points. The 6-foot-8 sophomore was able to draw a foul on UConn's Shonn Miller in the lane, and hit a jumper.
Clark and Farad Cobb scored 13 points apiece for the Bearcats (16-6, 6-3 American Athletic), who have won three straight and five of their last six.
Sterling Gibbs had 14 points to lead UConn (14-6, 4-3), which lost for the first time in four games.
Gibbs missed a running jumper on UConn's final possession. Miller grabbed the offensive rebound, but could not put in a follow-up attempt and Jalen Adams' desperation fall-away shot at the buzzer hit the rim and bounced away.
UConn coach Kevin Ollie screamed for a foul after Miller's layup attempt, but the graduate transfer was not making any excuses after the game.
''I've got to finish the layup,'' he said.
The Bearcats trailed by five at halftime, but held the Huskies to just 21 second-half points. UConn shot 38.3 percent from the floor - just 28 percent after intermission.
The Bearcats came in holding opponents to just over 39 percent shooting, while UConn's opponents were shooting 37 percent.
''They just play so hard, we play hard, a tough game to officiate,'' said Cincinnati coach Mick Cronin. ''It comes down to a couple plays at the end.''
Cincinnati trailed by seven points early in the second half before going on a 9-0 run. They took a 45-43 lead when Clark followed his own miss.
They had a 53-50 lead with 7:16 left in the game on a 3-pointer by Evans.
But the Bearcats did not score again until Evans' layup cut UConn's lead to 57-55 with a minute left.
Octavius Ellis chipped in 10 points and seven rebounds for Cincinnati.
Rodney Purvis had 12 points, while Miller and Adams had 11 apiece for UConn.
The Bearcats held the Huskies scoreless for almost four minutes and opened the game on an 8-2 run.
Three 3-pointers by Gibbs - on three consecutive trips down the floor - and another by Purvis highlighted a 16-4 run by UConn that helped the Huskies to a 36-31 halftime lead.
UConn came into the game 13-0 this season when leading at the half.
But the Huskies were just 1 of 8 from 3-point range in the second half after hitting five of their eight attempts in the first.
''UConn's a great team and this is a signature win,'' said Cobb.
Cincinnati came in ranked No. 69 in the latest RPI rankings and UConn was No. 58. Both teams have limited chances to improve that ranking the rest of the season, with No. 13 SMU as the only ranked team left on either schedule. UConn has two games left with the Mustangs. Cincinnati plays them once more, in their last regular-season game.
Cincinnati: The Bearcats had lost four in a row against UConn in Connecticut. Their last win came on Jan. 18, 2012, 70-67, at Gampel Pavilion in Storrs. ... Cincinnati's Shaq Thomas left the floor 3-minutes into the second half, favoring his right ankle after going to the floor at midcourt. Cronin said the injury involved both the ankle and his foot and he will undergo X-rays once the team gets back to Ohio.
UConn: Starting UConn center Amida Brimah missed his 11th straight game. Coach Kevin Ollie said Brimah's surgically repaired broken finger is healing and he should be back in about a week. Brimah was averaging 7.8 points and 3 blocks.
Cincinnati: The Bearcats return home to face USF on Thursday.