TUSCALOOSA, Ala. -- Hollis Thompson found just the right spot for a game-winning shot: Right in front of Georgetown's bench.

Thompson hit a long 3-pointer with 1.8 seconds left to lift the Hoyas to a 57-55 win over No. 12 Alabama on Thursday night, ending the Crimson Tide's 24-game home winning streak. Then he didn't have to go far for the celebration.

Jason Clark, who had 22 points, dribbled up the court and handed off to Thompson, who drilled it to give Georgetown (6-1) its second win in three games over a team ranked in the top 12.

"We drew a play trying to penetrate and they played it pretty well," Thompson said.

So he took the only option left, and delivered.

"Jason didn't have anything so he went to Hollis, and Hollis did what Hollis does," Georgetown coach John Thompson III said.

Alabama (7-1) had taken its second lead of the second half on Trevor Releford's two free throws with 13 seconds remaining. After a quick timeout by Georgetown, Clark and Hollis Thompson silenced a crowd thinking it was going to escape with the nearly 2-year-old streak alive.

Then, a ball screen and an apparent defensive mixup from Trevor Lacey and JaMychal Green helped get Thompson the contested shot.

"We didn't effectively defend that the way we were supposed to," Alabama coach Anthony Grant said. "Neither of the players that were involved defended it the way that we were supposed to."

The Tide rallied from a nine-point deficit over the final 3 minutes. Thompson hit the final two baskets for Georgetown, which also beat then-No. 8 Memphis in overtime last week.

Henry Sims scored 13 points and Thompson added 12 points and eight rebounds for the Hoyas, who came in averaging 82 points but matched Alabama's stingy defense stop for stop.

Tony Mitchell scored 16 of his 20 points in the second half for Alabama and finished off a couple of alley oops from Releford.

"He certainly ignited our team and the building," Grant said.

Green seldom got the ball inside against Georgetown's zone and scored six of his 13 points over the final 5 minutes. Releford had nine points and six assists.

"It just got us out of whack, and we weren't aggressive against the zone," Green said. "There's just a lot of things we could have done differently. Just getting the ball in the middle. Once you get the ball in the middle, it beats the zone and we really didn't do that."

Alabama's leading scorers Mitchell and Green combined for eight straight points after Georgetown took a 54-45 lead on a basket by Thompson with 2:57 left.

Clark came up big again against stiff competition for the Hoyas. He scored 26 and hit the go-ahead basket in overtime to beat Memphis.

"It was our third game against a team in the top 15," John Thompson said. "To come in and win against a team on their home court that's so well-coached, that's a big, big victory."

Clark made 4 of 7 3-pointers against a defense that came in holding opponents to 22 percent shooting from beyond the arc.

Georgetown exposed Alabama's biggest weakness. The Tide missed its first 11 3-point attempts after making just one from beyond the arc against VCU on Sunday night.

Freshman Trevor Lacey hit two in a row to end the drought, but Alabama still wound up 3 of 16.

Georgetown fought off rally attempts time and again. The Hoyas went up by eight points early in the second half, the Tide's largest deficit of the season at the time. Alabama closed within two points six times in the next few minutes and even took the lead briefly, but the Hoyas answered every time.

Sims scored seven straight points after Alabama grabbed a one-point lead, Clark drilled a 3-pointer and Thompson added a basket for that nine-point cushion.

The Hoyas mostly kept the ball out of Green's hands in the first half, taking a 23-16 lead and giving the Tide fits with their zone. It was the biggest deficit Alabama had faced all season.

Alabama missed all nine 3s in its lowest scoring opening half since scoring 16 at Oklahoma State last Dec. 18.

"They made the plays that they needed to make tonight," Grant said. "For us, too many breakdowns in the first half from an offensive standpoint in the second half from a defensive standpoint. Against a good team like Georgetown you can't afford that."