Thailand's Kiradech Aphibarnrat, whose stocky build and attacking style have drawn comparisons to John Daly, is a shock contender at the PGA Championship after adopting a more conservative approach.

The 24-year-old from Bangkok fired a two-under-par 68 at Oak Hill on Thursday in his debut at the year's final major tournament to grab a share of 11th, three shots behind co-leaders Adam Scott and Jim Furyk.

It was the the best opening round among Asian entrants.