Rory McIlroy waves to the gallery on the fourth green...

Rory McIlroy waves to the gallery on the fourth green after making a birdie during the third round. (Apr. 9, 2011) Credit: Getty Images

AUGUSTA, Ga. -- Had Rory McIlroy made the same downhill, curving 33-foot putt late this Sunday afternoon, it would have been appropriate for someone to say, "Yes sir!"

It might still be appropriate to say it Sunday if McIlroy keeps proving worthy of being a "sir" and not a kid any more.

The key moment occurred on Augusta National's 17th green, a day early but perhaps as a sign that McIlroy's time has arrived. The 21-year-old from Northern Ireland shot 70 Saturday to reach 12-under par and build a four-shot lead by making birdie on the very same piece of turf that Jack Nicklaus made his birdie putt in his win 25 years ago; a putt marked by the television announcer's call, "Yes sir!"

Will there be another "Yes sir" for him Sunday?

"I'm not getting ahead of myself," he said. "I know how leads can dwindle away very quickly. I have to go out there tomorrow, not take anything for granted and play as hard as I've played the last three days."

By not getting ahead of himself, McIlroy is in good company. No one else at the Masters has been able to get ahead of him, at least not for long. He was tied for the lead after the first round and was up by two after two. He did briefly fall behind fellow young lion Jason Day of Australia, but regained control.

It was not a day for much great golf, par being a good score among the leaders. McIlroy managed to go with that flow. He didn't receive a challenge from Tiger Woods, who had closed strong Friday. Woods shot 2 over par 74 yesterday, four shots worse than McIlroy. Defending champion Phil Mickelson shot 71 and is nine back.

The leader seemed as if he would be content to reach the clubhouse with a string of pars. Then his putt dropped on No. 17.

"I mean, it was a bonus," he said. "I hit the putt perfectly where I lined it up. It was tracking the whole way and just dropped in the middle. It was great, because I had been waiting on a putt to sort of drop all day. For it to drop there, it was great timing."

That putt left him four strokes ahead of his nearest pursuers, two-time major champion Angel Cabrera as well as Charl Schartzel, K.J. Choi and Day.

"Rory, the way he's hitting the ball, he can pretty much go out there and he can shoot a couple under par, I think, and probably win," Day said. "There's a lot of pressure on us to obviously go out there and score early and try and put some pressure on him so he can make some mistakes. But you know, he's very mentally tough. He's a great golfer and if he wins this thing tomorrow, he deserves it, definitely."

Nothing against the legacy of Nicklaus, whom McIlroy credits for direction during a 90-minute private talk last year. But McIlroy identifies more with the 1997 win by Woods, then 21. He says if he wins Sunday, it wouldn't rank with Woods' first green jacket.

"I remember watching it with my dad," he said. "That's when Tiger sort of grabbed all of our imaginations and won it by 12 and broke so many records. It was a huge moment for the game of golf. He's done more for the game than I ever could or will, breaking down barriers."

He says he won't be worried by what Woods or anyone else does Sunday. "I can only control what I do," he said. "And after three rounds, I've controlled what I can do pretty well."

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