SHANGHAI (REUTERS) - American Kevin Kisner continued his birdie barrage to take a two-shot halfway lead at the WGC-HSBC Champions, where stronger winds in China on Friday contributed to a frustrating day for a rusty Jordan Spieth and poorly Rory McIlroy.

While Kisner fired a bogey-free six-under 66 for a 130 total, world No. 2 Spieth could only muster a level par 72 to sit on 140 alongside McIlroy, who was still feeling the after effects of a bout of food poisoning.

The Northern Irishman, who said he had lost 4.5 kg because of the ailment, struggled again with his short game as he mixed four bogeys with four birdies in his round of 72.

The world No.3's frustrations boiled over with a rushed three-putt bogey on the 16th and he found water on the last with his approach but did well to get up and down for a par five.

"It wasn't a great day. I need to shoot a really good score over the weekend to give myself a chance. Hopefully, I can go out tomorrow and shoot something a little better and feel a bit better," the four-times Major winner said.

The 31-year-old Kisner, playing in China for the first time, had no such trouble as he followed up his opening 64 with another rash of red numbers at the Sheshan International Golf Course.

The South Carolina native was two clear of Scotland's Russell Knox, who managed a best-of-the day 65.

First round leader Branden Grace of South Africa was alone in third after a 71, while local fans were given plenty of reason to cheer by the form of 20-year-old Li Haotong.

Li fired a 69 that included a bogey five at his last following a wild approach into the water, to share fourth with American Patrick Reed (70) at 135.

Big-hitting Dustin Johnson, the 2013 champion, closed with three straight birdies for a 71 to share sixth with Austrian Bernd Wiesberger (66) and Hunter Mahan (68).