Defending champion Lee Westwood shared third place with Alvaro Quiros to remain as world number one.
Quiros was the only European player inside the top 10 after adding a 66 to his opening 69.
McIlroy started the final round three shots behind overnight leader Alvaro Quiros, who faded to a three-over-par 73.
Wood set the early clubhouse mark with a round of 68 while Quiros birdied the last three holes for the same total.
Quiros fired 64 to lead by four shots from Peter Hanson, who held the first-round lead but dropped back with a 72 on Friday.
The other three players to qualify for the Masters through the world ranking are South African Charl Schwartzel, Alvaro Quiros of Spain and Thai Thongchai Jaidee.
Zimbabwean Mike Kerr, who has worked with Alvaro Quiros and Ernie Els, will temporarily take over as caddy, while a new coach is already working with Westwood.
"Obviously they are fighting for the Race to Dubai final top position, but we are playing here to try to ruin the party, " Quiros said of McIlroy and Donald.
Woods carded a second consecutive five-under-par 67 to join overnight leader Nick Watney (70) on 10-under-par, with world number two Phil Mickelson returning a 66 to lie a shot behind alongside compatriot Ryan Moore and Spain's Alvaro Quiros.
Since posting a thrilling win in Qatar at the start of the year, which pushed the 26-year-old into the world's top 30, Quiros has struggled to recapture that form, with only a second place at May's European Open to show for his efforts.
The Bristol player led for a large part this afternoon but had to watch agonisingly as Quiros closed with three consecutive birdies to join him on 16-under 276 after a round of 69 and then see Oosthuizen's eagle put him back in contention.
Ahead of McIlroy and four shots back on the leaders in a tie for third are Jeev Milkha Singh of India and Colombia's Camilo Villegas, with Denmark's Soren Kjeldsen and Spain's Alvaro Quiros joining Americans Jim Furyk, Charley Hoffman and Kenny Perry on 11 under.
And although the South African, who is ranked 21 in the world, had the worst drive of the trio in the play-off, his second shot landed in the best position - Wood was more than 20 feet from the hole, while Quiros was just off the green.
应用推荐