Louisville: The players were facing a stop-start-stop-start day at the PGA Championship on Friday as heavy rain swept across Valhalla Golf Club with further thunderstorms expected.
Second-round play was suspended for 45 minutes less than half an hour after the first tee shots of the day were struck and tee times have since been pushed back 50 minutes.
The first stoppage was due to a situation described by organisers as "non-threatening" after greens and fairways were left waterlogged, forcing ground crews to use squeegees in a mop-up operation.
After four days of sunshine and muggy weather at Valhalla, a storm front has moved into the Louisville area and up to an inch-and-a-half of rain has been forecast for Friday.
Play was initially halted on Friday 45 minutes before British Open champion Rory McIlroy was set to start the second round, having opened with a five-under-par 66 on Thursday to sit one stroke off the pace.
McIlroy, the pre-tournament favourite who is bidding for a third consecutive victory on the PGA Tour, is now scheduled to tee off at 9:25 a.m. ET (1325 GMT).
Englishman Lee Westwood and Americans Kevin Chappell and Ryan Palmer led the year`s final major after firing six-under 65s in the first round, though both Westwood and Chappell were among the late starters on Friday.
Palmer, a three-times winner on the PGA Tour, was playing the first hole on Friday when the action was halted.
He later posted a picture of the water-logged first green and tweeted: "Sitting in the shot link tower on 1 watching it rain hard. Waiting it out they are saying. Really??"
While the heavy rain forecast for Friday will leave the greens more receptive to approach shots, it will make the 7,458-yard layout play much longer.