Rory McIlroy heard the roar and knew Tiger Woods had done something special.
The 22-year-old from Northern Ireland calmly lined up his eight-foot birdie putt and made it - just one of the tests he passed with flying colors Sunday for a Honda Classic victory that propelled him to number one in the world golf rankings.
"I could hear the huge roar," McIlroy said. "And it definitely wasn't a birdie roar."
The cheering was for Woods's eagle on the final hole, which momentarily pulled the 14-time major champion within one shot of McIlroy.
McIlroy made his birdie at 13 to stretch the gap back to two, and delivered a series of clutch par putts coming home to seal the victory.
"It was always a dream of mine to become the world number one and the best player in the world or whatever you want to call it," McIlroy said.
"But I didn't know that I would be able to get here this quickly. ... Hopefully, I can hold onto it for a little longer."
McIlroy, whose resume includes a record-setting US Open victory at Congressional last year, was celebrating by flying to New York to see his girlfriend, Danish tennis player Caroline Wozniacki - herself a former world number one in her sport.
He was due back in Florida later in the week for the World Golf Championships event at Doral.
It was the second week in a row that McIlroy had a chance to supplant Luke Donald at the top of the world rankings. He missed out at the WGC Match Play Championships when he fell in the final to American Hunter Mahan.
This time around, despite the pressure from Woods, McIlroy held on, single putting four of the last six holes.
Northern Ireland's Graeme McDowell was delighted for his compatriot, and for the excitement that Sunday's final round promised for the rest of the season.
Not only did Woods pour on the pressure with his closing 62, England's Lee Westwood rocketed up the leaderboard with a fourth-round 63.
"It was a lot of fun out there today," McDowell said. "For Rory to go out today with a two-shot lead and have Tiger shoot 62 on him and Westwood shoot 63 ... this golf season just got a lot more spicy."
McDowell said McIlroy, who becomes the second-youngest player behind Woods to rise to number one, was helped by his improved putting.
"That was the missing link, because the rest of his game is all there," McDowell said. "As soon as he learned how to putt, he was going to be a dominating force, and you're starting to see that now."
Donald, who did not play in Florida this week, was quick to offer his congratulations via Twitter.
"Congrats @McIlroyRory enjoy the view!" the Englishman tweeted.
But former number one Woods - who has not won a tour-level title in more than two years - garnered as much attention as the new number one.
Still the biggest draw in golf, the 14-time major champion demonstrated he is ready to rekindle his stalled pursuit of Jack Nicklaus' record of 18 major titles.
That can only be good for the game, McDowell said.
"I'm excited to be part of golf right now," he said. "It's great to have Tiger Woods back playing the kind of golf we know he can play, because he's exciting for golf...
"I think Rory ... he's working harder and he has a huge amount more belief in himself and he knows what he wants to do now and he knows how to do it."