Robert-Jan Derksen and Charl Schwartzel shared a one-stroke lead on the second day at the UBS Hong Kong Open after the duo improved to eight under par.

With PGA Championship winner YE Yang (67) and Malaysia's Danny Chia (66) in the clubhouse at seven under after battling the overcast morning conditions, Derksen and Schwartzel set about creating a halfway lead in afternoon sunshine.

Derksen, second overnight following a first round 63, began with a disappointing double bogey but a run of three straight birdies left the former Dubai Desert Classic champion one under for the round at the turn.

South African Schwartzel picked up three shots in four holes at the start of his back nine to build on his bogey-free first round 65.

David Dixon, who needs a solid performance this week to be assured of his card for next season, and defending champion Lin Wen-tang sit at seven under after building on their first rounds of 64.

Peter Lawrie (68) and India's SSP Chowrasia (69) are safely in the clubhouse at six under, with Rory McIlory, South Africa's Rory Sabbatini and China's Liang Wen-chong improving to that mark during their second rounds.

Race to Dubai contender McIlory picked up two birdies over his front nine, but it could have been so much better for the Holywood ace after missing a two-foot birdie putt at nine before seeing a six-foot chance at 12 lip out.

Race to Dubai leader Lee Westwood, who leads McIlroy by a mere 52,321 euros with just two events remaining, played the first 13 holes of his second round in level par to remain at four under.

First round leader Udorn Duangdecha tumbled down the leaderboard as the Thai failed to follow on from his storming 62 with a four-over-par 74 which included four bogeys and a double-bogey.

Meanwhile, 15-year-old Hong Kong amateur Jason Hak is set to make the cut for a second successive year after carding a second round three-under-par 67.

Last year, playing in his first European Tour event, US-based Hak became the youngest player to make the cut in Tour history after beating Sergio Garcia's record which had stood for 13 years.

And returning this year on a sponsor's invite after qualifying as a 14-year-old 12 months ago, his three-under-par total will comfortably secure a berth over the weekend.

"I enjoyed today very much. I had five birdies and misread it a bit on the two bogey holes. My iron shots were great, but I think I need to work on my putting," he said.

"Over the weekend I will try and enjoy playing with the international stars and use the same gameplan. I will try and take it easy and not put too much pressure on myself."