It’s easy to grow accustomed to crucial shots making the difference in close games in the tournament. But it was an emphatic block by No. 5 Arizona’s sophomore forward Derrick Williams that finally iced a 77-75 victory over No. 12 Memphis in West Region action in Tulsa on Friday.

Charlie Riedel/AP
Arizona's Lamont Jones reacts after forward Derrick Williams, right, blocked a shot by Memphis' Wesley Witherspoon's in the final seconds of play at a West Regional NCAA tournament second round college basketball game, Friday, March 18, 2011 in Tulsa, Okla.