Jason Day
Day is twice a runner-up at major championships. Getty Images

Australian pair Jason Day and Matt Jones co-lead the US PGA Championship after play was abandoned during round two at Whistling Straits. The pair were locked at nine-under when organisers halted proceedings due to an electrical storm in the Wisconsin area.

England's Justin Rose is third on eight-under, while Harris English and Tony Finau are a shot further back on seven-under. Memorial champion David Lingmerth of Sweden is the clubhouse leader on seven under ahead of Jordan Spieth who continues to dazzle during a stellar 2015.

"I feel good," the Masters and US Open champion said. "I made a couple putts today. With a couple chip-ins for the week and really smart course management and good speed control, we have been able to hold ourselves in there."

Lingmerth added: "I really had to fight today. The wind was easier than yesterday so there are some scores out there to be had. I was able to make a bunch of birdies but doubles and bogeys set me back so I had to fight to end under par."

The American dominated leaderboard sees Spieth joined on six-under by home favourites Scott Piercy, Brendan Steele, Russell Henley and J.B Holmes. First rounder leader Dustin Johnson however endured a torrid time with a run of four dropped shots in eight holes as his challenge faded badly.

Prior to the round-ending storm, early conditions were good for low scoring and that led to Japan's Hiroshi Iwata shooting the joint-lowest round in major history with a nine-under 63, to go to four-under. The 34-year-old became the 27th player to achieve the feat, and the 13th in US PGA Championship history.

Players were hauled off with 19 groups still out on the course and when the storms hit tournaments administrators suspended play for the day indefinitely. After stormy weather saw July's Open Championship finish on a Monday for the second time in its history, the 97th US PGA Championship threatens to be beset with similar delays.