First-year Alabama coach Avery Johnson said he learned something from forward Riley Norris' first start of the season Wednesday night.

"Maybe I should have been starting him a little earlier," Johnson said.

Norris' career-high 27 points led the Crimson Tide to a stunning 73-50 Southeastern Conference rout of previously unbeaten South Carolina at Coleman Coliseum in Tuscaloosa, Ala.

Norris did almost all his damage from the 3-point line, canning 8-of-11 from distance, including 5-of-5 in the first half as Alabama (10-5, 1-2) established a 19-4 lead and never looked back.

"I think it was a great boost," Norris said of his eight 3s, "but you have to give all the credit to my teammates. They were the ones driving the lane, giving me the shots. All I had to do was knock them down."

It was the Crimson Tide's third win over a Top 25 team this season and by far their easiest. They never trailed and led by as many as 27 points in the second half, turning the game's final 14 minutes into a race to the final horn.

The 19th-ranked Gamecocks entered the night as one of only two undefeated teams in Division I, but their 40-minute pratfall left No. 10 SMU as the last unbeaten.

Held 30 points below its season average, South Carolina (15-1, 2-1) made just 35.8 percent of its shots and committed 18 turnovers, leading to 23 Alabama points. In a 14-minute stretch bridging the halves, it failed on 17 straight field goal tries.

"We were bad, but give Alabama credit," Gamecocks coach Frank Martin said. "They got us."

South Carolina started and ended the first half with turnovers, the Crimson Tide converting each one into points to bookend a 35-22 first half that marked the Gamecocks' lowest-scoring first half of the season.

With Heisman Trophy winner Derrick Henry and several members of Alabama's national championship football team looking on from courtside seats, the Crimson Tide opened the second half with the kind of physical domination Nick Saban would appreciate, scoring 13 unanswered points for a 26-point lead.

Johnson, who attended Monday night's 45-40 win over Clemson, hinted that game offered his team some momentum.

"We had to defend the paint," Johnson said. "We had our hardest practice of the year yesterday and it carried over into tonight. It's all about consistency."

Point guard Justin Coleman came off the bench to supply 14 points, six assists and five rebounds for Alabama, often finding Norris off penetration.

While the Crimson Tide basked in the glow of a complete effort, Martin said his team has to avoid the prolonged losing streaks that have marked its efforts in conference play since he arrived from Kansas State in March of 2012.

"We've allowed a loss to become two and three," he said. "We can't allow that to happen. The teams that are pretty good answer after a bad performance."

Forward Michael Carrera scored 14 points and grabbed 10 rebounds for South Carolina.

NOTES: Alabama's first three SEC opponents -- Mississippi, Kentucky and South Carolina have a combined overall record of 39-6. ... Gamecocks G Sindarius Thornwell became the 42nd player in program history to pass 1,000 career points with 19 in Saturday's win over Vanderbilt. ... South Carolina's ranking of 19th in this week's Associated Press poll is its highest since 1998.