Woods, who shot 1-under 71 today, is looking to win his first major of the year and 15th overall. He is 36-1 when he has the lead going into the final round, 14-0 at the majors.
Woods is at 8-under 208. Harrington, who had a share of the lead with five holes to go, bogeyed 18 and is at 210. Yang will play with Woods on Sunday; he beat the world's No. 1 player at the HSBC Champions in China in 2006.
Manageable playing conditions and a so-so outing by Woods allowed other players to make a charge. But just like Friday, Woods made shots when he had to and the others fell away.