"This is my last shot at it, so you don't want to just play one game and go home right away," Gates said. "I'll never play in the Garden in the Big East Tournament again, so just trying to push and fight and stay here as long as possible."
Georgetown's Otto Porter sent the game to overtime when his jumper bounced in with 3.6 seconds remaining in regulation.
Sims, who had 22 points and 15 rebounds, hit a layup at the buzzer to force a second OT for the Hoyas (23-8). Well out of his range, Sims missed a potential winning three-pointer at the close of the final period.
"I'd much rather have that shot at the end," he said.
The Bearcats will play No. 2 Syracuse in tonight's semifinal.
Cincinnati won despite missing 19 of 21 three-point attempts. Dion Dixon, who scored 22 points in a Cincy road win in the teams' first meeting, was 4-for-17 from the field, 0-for-6 from behind the arc and 5-for-9 from the foul line.
"Today was a great example of the character of our team," coach Mick Cronin said. "So I couldn't be more proud of these guys right now, to go 2-for-21 from three against Georgetown and win the game is unthinkable, to be honest with you."
In other games *
Eric Atkins scored all six of his points in overtime and No. 23 Notre Dame beat South Florida, 57-53.
The third-seeded Fighting Irish (22-10) will play seventh-seeded Louisville in the semifinals tonight.
Pat Connaughton and Jerian Grant had 12 points each for Notre Dame, which will be making its fifth semifinal appearance, but has never made it to the title game.
Victor Rudd Jr. had 16 points for the sixth-seeded Bulls (20-13).
* Kyle Kuric scored 20 points, Peyton Siva added 18 and Louisville (24-9) forced No. 9 Marquette into a season-high 26 turnovers to advance to the semifinals with an 84-71 victory. Darius Johnson-Odom had 23 points to pace the Golden Eagles (25-7).
The Cardinals held Big East Player of the Year Jae Crowder to 10 points in 31 foul-plagued minutes. Russ Smith and Chane Behanan each scored 12 points for Louisville (24-9).
Darius Johnson-Odom had 23 points to pace No. 2 seed Marquette (25-7), blown out by Louisville in the quarterfinals last year as well.
* Dion Waiters had 18 points and James Southerland scored all 10 of his points over the final 8 minutes to lead No. 2 Syracuse (31-1) to a 58-55 win over Connecticut.
The top-seeded Orange (31-1) won its 11th straight game overall.
Shabazz Napier had 15 points and Andre Drummond added 14 for the ninth-seeded Huskies (20-13).