American Peter Uihlein vowed to maintain his uncomplicated approach in pursuit of a second European Tour title after taking the halfway lead in the Shenzhen International on Friday.

Uihlein added a second round of 68 to his opening 67 at Genzon Golf Club to finish nine under par, one shot ahead of Thailand's Kiradech Aphibarnrat, while two-time Masters champion Bubba Watson struggled to a 74 to lie nine shots off the pace on level par.

Michael Hoey was the only Irish player to make the cut after carding a second round 71 to move to one over for the tournament.

Damien McGraine missed out on five over, Peter Lawrie finished six over and Kevin Phelan was a further shot behind.

"It was tricky today. The wind was swirling quite a bit," Uihlein told after carding five birdies and just one bogey.

"I got the back nine out of the way pretty quickly. I played very solid. I felt like getting anything under par on the back nine was nice, and I played a pretty stress free front nine which is always good.

"I don't have much going on upstairs, just spacing out, doing my own thing and sticking to my own game plan.

"I don't really change it very often. It worked the first couple days so I'll see how it goes from there."

Aphibarnrat, whose sole European Tour title to date came in the Maybank Malaysian Open in 2013, had held the lead for much of the day after five birdies and two bogeys in his 69.

The 25-year-old, who finished sixth in the Arnold Palmer Invitational at Bay Hill last month, said: "It was a great round. Again, the wind was getting up on a few holes before I finished, but the way I was striking the ball is still very good.

"When I go out worldwide, I learn a lot of experience and I saw many top players play. Even this week, we have Bubba Watson around.

"So it's been helping Asian players to keep improving when we see all the star players, how they are playing the shots, and I just adapt it to my golf game and it's improving."

Aphibarnrat was two shots ahead of Argentina's Emiliano Grillo, who birdied six of his last 10 holes for a 67, France's Gregory Havret, England's Matt Ford and South African Darren Fichardt.

Ford had been eight under par until bogeys on the 14th and 16th, while Fichardt also suffered from a poor finish following a hat-trick of bogeys from the 14th.

Watson, who had blamed poor putting for failing to put up a better defence of his Masters title last week, was already two over par for the day when he three-putted the seventh, before another three-putt from long range on the ninth meant he had to settle for a par after hitting the green on the 536-yard par five in two.

At that stage the left-hander was one over par and flirting with missing the cut, but birdied the 10th and 13th and bounced back from a bogey on the 15th with another birdie on the 16th, before dropping another shot on the 18th.

Italy's Edoardo Molinari had earlier been disqualified for signing for an incorrect score in his opening 75, the former Ryder Cup player failing to include an unusual penalty incurred by his caddie.

Molinari wrote on Twitter: "Got DQ because my caddy jumped on a buggy between the 9th and the 10th hole yesterday. I didn't see him unfortunately as I was 20 yards ahead.

"It would have been a two stroke penalty had I found out yesterday, DQ because I signed for the wrong card (which didn't include the penalty)."

Korea's An Byeong-hun could also count himself unfortunate after being forced to withdrew due to a neck injury. An was just one shot off the lead after an opening 67 which included a hole-in-one on the eighth, but was five over par for his second round before calling it a day after 14 holes.