Rory McIlroy's magical run in the WGC-Accenture Match Play came to an end when he lost 2 and 1 to a clinical Geoff Ogilvy at the Ritz-Carlton Golf Club.
But the Holywood teenager, 19, left Tucson with his held held high after forcing the Australian major champion to birdie the 15th, 16th and 17th to shade a thrilling desert showdown.
McIlroy said: "I couldn’t have done much more. Geoff just played great today. I expected it as he is a major champion and has won two world golf championships. I made a few birdies but Geoff made a few more and I couldn’t do anything about it. I think he will be very hard to beat.
"He got two up on me after 12 and didn’t birdie the par five so I managed to get one back. But then he threw three in a row at me to finish me off. I just tried to keep doing what I was doing and making birdies and it was very nice to make that putt on the 16th to keep the match going. But then he holed one on 17 to shut me out.
"But I have taken a lot from it. It is my first time in America and I have played great which has given me a lot of confidence to take into the next two weeks."
Ogilvy knew he was in for a tough match and reeled off eight birdies and just one bogey to extended his record to 15 wins and just two defeats since he won the title in 2006.
Impressed by McIlroy, he said: "He is going to be a top ten player for as long as he wants to be. I hit the ball the best I have hit it this week and I knew I had to play well against Rory because he has made short work of the other guys he has played so far."
McIlroy got off to a good start with a winning birdie four at the second but lost the fourth and fifth to birdies by the teak tough Aussie to go one down.
The Ulster ace levelled the match with an 18 foot par save at the ninth but drove into the desert to lose the par five 11th and then went two down at the short 12th, where Ogilvy rolled in a 15 footer
McIlroy closed the gap to one hole with a birdie at the 13th but hit a poor bunker shot and lost the driveable 15th to a birdie to go two down again.
At the 16th, Ogilvy looked certain to win the hole when he drained a 12 footer for a two. But McIlroy followed him in to take the match to the 17th.
However, it all ended there as Ogilvy hit a 199 yard approach to 14 feet and with McIlroy just eight feet away, rolled in the putt to progress to the semi-finals against Stewart Cink, who beat Ernie Els 2 and 1.
In the other half of the draw, England's Paul Casey beat an out of form Sean O'Hair 4 and 3 and will face compatriot Ross Fisher, who beat Justin Leonard 2 and 1.