Fowler, Stenson share lead in PGA title fight
Rickie Fowler of the United States hits his tee shot on the fifth hole during the final round of the 96th PGA Championship at Valhalla Golf Club on August 10, 2014 in Louisville, Kentucky - by Jeff Gross
Sweden's fourth-ranked Stenson, seeking his first major title, made four birdies in his first seven holes to claim his share of the top spot.
Rickie Fowler's 20-foot chip-in at the fifth capped a run of three birdies and put him on 13-under as well.
Five-time major winner Phil Mickelson was on 12-under with four-time major winner Ernie Els on 11-under with Finland's Mikko Ilonen, Austrian Bernd Wiesberger and Rory McIlroy, who missed a six-foot par putt to bogey the sixth, his second bogey of the day.
Fowler, a runner-up at the British and US Opens, stood on 13-under par after seven holes at rain-soaked Valhalla, where drenched greens offered plentiful birdie chances to golf's top stars.
Fowler, who also shared fifth at the Masters, could collect his first major title at age 25 and become the first player since Tiger Woods in 2005 to finish in the top-five in all four majors in the same year.
Only Woods and Jack Nicklaus have achieved the feat, each doing so twice and in every case always winning at least once.