(Reuters) - Tiger Woods delivered the best possible response to suggestions earlier this week that he is intimidated by Rory McIlroy as he outscored the world number one by three shots in the Tour Championship first round on Thursday.

Playing with the mop-haired Northern Irishman in the final pairing in front of huge galleries at East Lake Golf Club, Woods birdied two of the last four holes for a four-under-par 66 to burst into a share of the lead.

McIlroy, who led the FedExCup points standings coming into the PGA Tour's fourth and final playoff event, carded a 69 in his first competitive round on the challenging East Lake layout.

"I enjoy playing with Rory," Woods, 36, told reporters after joining Britain's Justin Rose atop the leaderboard in the 2012 FedExCup finale.

"He's a great kid. Over the years there are certain pairings for me that I've enjoyed, and Rory is one of them."

Woods, a three-times winner on the PGA Tour this season, was paired with McIlroy for a fifth time in this year's FedExCup playoffs, a perfect scenario for television ratings as well as for the East Lake fans.

"I think that is the whole idea of the playoffs, trying to get the top players all playing more often but also in the same group," said world number two Woods, who won the Tour Championship in 1999 and 2007.

"You figure the top players are going to gravitate towards the top of the points list and hence, you're going to have these types of pairings throughout the playoffs. And it's turned out that way this year.

McIlroy, who has overshadowed Woods this season by winning four times, including his second major title at last month's PGA Championship, relished playing again with the American former world number one.

"It was great," the 23-year-old Northern Irishman said. "I always say with groupings like that, it's a great atmosphere and it's a great buzz. I wish I could have shot a couple of shots better.

"But I'm in a good position going into tomorrow. I'll just go out there and try to play the same way, maybe hole a few more putts and turn what I shot today into something in the mid-60s."

BURGEONING RIVALRY

McIlroy and Woods enjoy a burgeoning rivalry and appear to thrive in one another's company. Thursday was no exception as they laughed and joked while striding down the first fairway before treating the fans to a series of clutch putts.

Woods rammed in a 21-foot birdie putt at the par-three second, then McIlroy followed suit with a slippery 18-footer downhill to birdie the third.

The American chipped in to birdie the 12th, and McIlroy responded by draining a 22-footer. Woods finished the stronger though, birdies at 15 and 16 putting him level with Rose in a tie for the lead.

All this after former world number one Greg Norman of Australia had sparked debate earlier in the week when he told FoxSports.com that Woods had effectively handed over the baton to McIlroy as the game's leading player.

"What I'm seeing is that Tiger's really intimidated by Rory," Norman said. "When have you ever seen him intimidated by another player? Never."

Both Woods and McIlroy laughed off Norman's suggestions in the build-up to the Tour Championship, although the American was certainly the happier with his position heading into Friday's second round.

"As a whole, I played well today. I hit a lot of good shots, made a few putts out there, but actually I had a couple of good up-and-downs, which is nice," said Woods.

"I prefer the old, traditional golf courses like this. Trouble is just right there in front of you. It's very simple, but it's hard."