MEMPHIS, Tenn. -- No. 1 seed North Carolina has a 32-23 lead over No. 2 seed Oklahoma at halftime of Sunday's South Regional final at FedExForum. Here's a few observations from the first 20 minutes: • Oklahoma's Blake Griffin is probably winning the All-America battle against UNC's Tyler Hansbrough, but he isn't getting enough help from his OU teammates. The Tar Heels are doing a great job defending Griffin, denying him the ball in the post with constant double- and triple-teams. UNC coach Roy Williams is throwing an assortment of big men at Griffin, including Deon Thompson, Tyler Zeller and Ed Davis. • Griffin scored 11 points in the first half, but took only four shots from the floor. He went 5-for-7 on foul shots, which drew some boos from the pro-Carolina crowd. Now they know what most UNC opponents feel like when Hansbrough goes to the line seemingly every trip. • Hansbrough picked up two early personal fouls and sat on the bench for 11 of the 20 minutes. He scored four points on 2-for-3 shooting and grabbed one rebound in the first 20 minutes. • I don't know that I've ever seen a better rebounder at the college level than Griffin. He has nine of the Sooners' 18 rebounds in the half and gets great position to pull the ball down. Still, UNC is hanging with OU on the boards; the Sooners have an 18-15 advantage in rebounds. • If Oklahoma is going to come back, it's going to have to start making some 3-pointers. The Sooners were 0-for-9 from beyond the 3-point line in the first half. Guard Tony Crocker, who scored 28 points against Syracuse in the Sweet 16, never got in a rhythm in the first half against UNC. He picked up two early fouls and went scoreless on 0-for-3 shooting in seven minutes. Freshman Willie Warren is also going to have to shoot the ball better in the second half, after going 1-for-5 and 0-for-3 on 3-pointers. • OU point guard Austin Johnson is holding his own against UNC's Ty Lawson. Johnson didn't score in the first half, but he didn't turn the ball over once. Lawson scored four points on 2-for-6 shooting. OU has to do a better job of taking care of the ball, though; the Heels scored 13 points off nine turnovers.