Ernie Els and his 3 year plan

Ernie Els has laid out a three-year battle plan to challenge Tiger Woods as world number one.

Buoyed by his triumph at the South African Open on Sunday, a victory that allowed Els to maintain his record of winning at least once a year since 1991, he said his sights were now firmly set on his American rival.

"I see 2007 as the start of a three-year plan where I totally re-dedicate myself to the game," the South African told his official Web site. "I want to win more majors and start giving Tiger a run for his money.

"If you look at where he is at the top of the rankings, it's a big lead so no one is going to get near him any time soon. I've got to give myself a three-year stretch to try to approach him and I really believe I can do it."

Woods has 20.41 ranking points and a huge advantage over countryman Jim Furyk (8.88) in second place. Els is fifth on 6.05.

Three-times major champion Els said he was in better physical shape than he had been for a long time.

"I'm fitter than I have been since I came out of the army," said the 37-year-old.

"My knee is strong and the important thing is I trust it, I really trust it. That means I can swing the club the way I want to, without feeling I have to protect it in any way.

"I can really start moving forwards now and concentrating on my goals."

Els's game was hampered for a long time after he injured his knee on a family sailing holiday in the Mediterranean last year.

"I'm a very happy man," he said. "Since I returned to competitive golf just over 12 months ago, after injuring my knee following the 2005 British Open in July, I've basically been playing patch-up golf.

"As hard as I tried, it just wasn't happening for me. It was frustrating.

"The South African Open was my last chance to set the record straight. Now I've done that the relief is immense."