Rory McIlroy survived a sudden-death play-off to keep his hopes of a second successive WGC-Dell Match Play title alive.
McIlroy, who has never successfully defended a tournament in his professional career, defeated American Kevin Na on the second extra hole of their winner-takes-all contest to advance to the last 16 at Austin Country Club.
The world number three found himself two down after a double bogey on the second and a Na birdie on the fifth, but bounced back with a birdie on the seventh and then holed from 65 feet on the ninth to get back on level terms.
Na reclaimed the lead with a birdie on the 10th but McIlroy’s new putting technique again paid dividends as he holed from 30 feet on the next, before edging in front for the first time on the 15th.
However, McIlroy drove into the water on the 16th and Na won the hole with a birdie four, with neither player then able to secure victory in regulation or on the first extra hole.
Na then hooked his tee shot on the second into a hazard, and a par from McIlroy was enough to secure a meeting with Open champion Zach Johnson, who had earlier defeated Shane Lowry 4&3 to complete a perfect 3-0 record in group 14.
“I had to dig pretty deep,” McIlroy said. “Kevin is a very good competitor and he was not really giving me much out there. I holed a few long putts to keep it together when I needed to.
“I had a couple of chances to maybe close the match out on the last and the first extra hole but for the most part I felt I played pretty well. I responded to some of his good shots with good shots myself and that gives me confidence going into the weekend.
“But it does not get any easier. This is a course that really sets up well for Zach. It’s a precision type of course and if he gets the ball in play he will be very hard to beat. I feel like my match-play game is pretty good and no matter what he does I am going to have to respond to it.”
Meanwhile, Graeme McDowell halved his match with Thongchai Jaidee, while Shane Lowry lost to Zach Johnson 4 and 3.
Jason Day had been the first player into the last 16 after his final group two opponent Paul Casey was forced to withdraw from their contest after six holes due to a stomach virus.
“Unfortunately Paul has some stomach virus and I overheard him say he has lost eight pounds since he has had it and that drains the energy out of you,” Day said.