HOYLAKE, England, July 21 (Reuters) - Jack Nicklaus and Tiger Woods have combined to salute Rory McIlroy's performance in capturing the British Open title for the first time in his career.

The 25-year-old Northern Irishman became the third youngest golfer in the modern era, after the two American greats, to land three of the four major championships when he triumphed by two strokes at Royal Liverpool on Sunday.

"I like his swagger," said 18-times major winner Nicklaus on his official Facebook page. "I like the way he handles himself.

"I like his desire to be great. I like his desire to do the things he needs to do. I like that in a young guy. He's cocky in a nice way."

McIlroy went into the last day holding a six-stroke lead and Nicklaus said he was particularly impressed with the way he protected his advantage with a safety-first 71 in the final round.

"He didn't take some of the chances that he did in the other rounds as far as the clubs he hit off the tee," added the Golden Bear.

"Rory didn't put himself in position to lose the golf tournament. He did what he needed to do … It's about shooting what you have to shoot to win the golf tournament."

Woods, who finished 69th of the 72 players who made the cut at Royal Liverpool in only his second competitive appearance since undergoing back surgery in March, compared new world number two McIlroy to his great rival Phil Mickelson.

"The way Rory plays is pretty aggressively," said the 14-times major champion. "When he gets it going, he gets it going. When it gets going bad, it gets going real bad - it's one or the other.

"He's very similar to what Phil does. He has his hot weeks and he has his weeks where he's off. And that's just the nature of how he plays the game.

"He hasn't really been making the amount of putts that he did a couple of years ago, but now he's starting to make those 10- to 15-footers. That turns rounds around," Woods said.

"You make two or three birdies in a row, you make a par putt here and there. Next thing you know a round where you would normally shoot one- or two-over and all of a sudden it's a 69 and then you get the hot round and it's a 66 or 65."

GREAT PERFORMANCES

Mickelson said it would be tough for McIlroy, who has only Australian Adam Scott ahead of him in the rankings, to dominate world golf the way Woods and Nicklaus once did.

"We used to say there will never be another Nicklaus and then along came Tiger," said the five-times major winner.

"You never want to discount the possibility of someone coming along and dominating but nobody has really asserted themselves week in and week out the way Tiger did for such a long period of time.

"We'll have great performances, like Rory this week, like Martin Kaymer at last month's U.S. Open … but it's very hard to do that week in and week out the way Tiger did."

McIlroy's Ryder Cup partner Graeme McDowell said the acid test for his friend now was to continue to score well on a consistent basis even when he was not at his best.

"Tiger had that capability of getting the job done ugly," said McDowell after finishing tied ninth at Hoylake. "Perhaps Rory has to prove he's got that side to him.

"I can just sort of sit back and admire how good Rory is and we'll watch from there. But the third leg of the major grand slam at 25 - that's pretty good."

(Editing by Stephen Wood)