Rory McIlroy's bid to become the first man in half a century to retain the $2-million UBS Hong Kong Open came to an embarrassing end on Friday as the world number one crashed out with a double-bogey.
With the 23-year-old missing the halfway cut after a disastrous second round, New Zealander Michael Campbell surged to the top of the leaderboard, the tournament now wide open after McIlroy's meltdown.
Campbell, who won the US Open in 2005 but has struggled since, took the lead in blustery conditions with a 64 that was studded with seven birdies against a lone bogey for a two-day total of nine-under-par 131.
Miguel Angel Jimenez of Spain, China's Zhang Lianwei and the Swede Fredrik Andersson Hed were tied in second, a shot behind, at Hong Kong Golf Club.
McIlroy, whose third place in Singapore last weekend saw him tie up the European money list to add to his United States cash crown, started his second round brightly, making three birdies in his opening six holes.
But then the wheels came off. With the wind picking up under rolling clouds, the Northern Irishman went on a rotten run: he had four bogeys in five holes, made par on his penultimate hole, then finished with a double-bogey.
His round of two-over-par 72 left the starlet on five-over for the tournament, three shots shy of the cut. He previously failed to make three cuts in May-June, including at the US Open, where he was defending champion.
"I always enjoy coming back here, it's just a pity that this year had to end like that," said McIlroy, who audibly groaned when his approach shot went wayward on the fifth hole, to gasps from the large watching crowd.
"The wind was tricky. It definitely made play a little trickier. I didn't putt very well in Singapore last week. This week was the same, so a bit of putting practice is required in Dubai," he said.
What had until then been a hugely satisfying season for McIlroy concludes at the lucrative DP World Tour Championship next weekend. He has already sealed the Race to Dubai.
"If I was completely fresh I wouldn't have been making the mistakes I was making. I've got a couple of days to rest and then get ready for Dubai," added McIlroy, who said Thursday after his first-round 73 that he felt "lethargic".
"I got off to a great start. I was minus-four for the first 10 holes or whatever and had a chance to go to minus-five and then I just started going the other way."
The last player to retain the Hong Kong Open was Taiwan's Hsieh Yung-yo in 1964. Two other high-profile casualties of the cut on Friday were the South Korean Y.E. Yang and former Hong Kong Open champion Padraig Harrington.
At the other end of the leaderboard, Campbell, 43, showed the kind of scintillating form that made him New Zealand's first Major winner seven years ago.
"That makes it a lot easier," he said, after learning about McIlroy. "Obviously he's the best player in the world for a reason.
"He's a wonderful talent and I admired him since he turned pro. He was very impressive then, and what he's done for the game has been fantastic. I guess for this week it makes winning the Hong Kong Open easier, definitely."
Anders Hansen of Denmark was fifth, two shots off Campbell. Japan's Daisuke Kataoka and the shock overnight leader, unknown Spaniard Javier Colomo, were tied sixth.