Ryo Ishikawa
The first round was significantly delayed when a storm blew in shortly after play began on Thursday. Play was resumed in the afternoon, but almost all players were still on the course when darkness fell. At this point, Hunter Mahan led the field at 7-under-par through his first 11 holes, and held on to the lead when the first round was concluded on Friday morning. Teenager Ryo Ishikawa was one shot back in second, while new world number one Martin Kaymer was third; several players including Luke Donald and Matt Kuchar had reached the 6-under mark in their rounds, then dropped back.