The second round was scheduled to resume at 7:15 AM CDT, but rains saturated the Hazeltine National Golf Club, pushing back the start time two hours.
Funk is one of 41 players who has to complete his second 18 holes.
Retief Goosen (69), Justin Leonard (66), Mark Calcavecchia (68) and Rich Beem (66) are all in the clubhouse, tied at minus 6.
Friday marked the second straight day that lightning had factored at Hazeltine. Thursday, the elements postponed play for nearly three hours, forcing 39 players to complete their opening rounds Friday morning.
In 1991, lightning killed one spectator and sent six others to the hospital in the first round of the U.S. Open at Hazeltine.
Though rain and lightning aren't in the forecast Saturday, 30-40 mph winds are.
'I can't imagine that kind of wind and playing this golf course and trying to get the ball to stay in the fairway,' said Funk, one of the most accurate drivers on the PGA Tour.
If thats the case, it will be similar to the conditions faced in the third round of the preceding major.
At Muirfield, 40 mph gusts blew away Tiger Woods chance for a seasonal Grand Slam. He shot 81 under treacherous conditions to fall out of contention in the British Open.
Hes once again in contention this week, at 3-under-par for the tournament through 16 holes.
After starting his second round with a 15-foot par save at the first, Woods made three birdies in a four-hole stretch to get to 4-under for the tournament. But after missing a seven-footer for birdie at the eighth, Tigers round stalled. He made five straight pars before three-putting for bogey at the 13th.
Funk began the round tied with Jim Furyk. But while Furyk shot 73 to drop to 3-under, Funk continued to progress.
The five-time PGA Tour winner started on the back nine and birdied Nos. 10, 13 and 15 to take sole possession of the lead at 7-under.
Funk missed the fairway at the par-4 first and had to pitch out into the fairway. He was left with a 10-footer for par, but made the save.
Funk took a two-shot lead with a birdie on the par-5 third, but gave it right back with a bogey at 4.
He was quite animated throught the round, swinging his putter when left a ball short of the hole, pumping his fist when they fell, and hi-fiving everyone with an extended hand.
'I wasn't scared of the atmosphere I was in,' said Funk. 'I was having fun. I was enjoying being in the lead at the PGA.
'I'm not going to back down.'
The quartet of players at minus 6 all posted their numbers in the morning, and all but Beem are past major champions.
Calcavecchia is making his 50th major start since winning the 1989 British Open, and the big events have seen little results. The 42-year-old has but three top-10 finishes in majors since his British triumph, two of which came last year. He tied for fourth in the 2001 Masters and recorded the same result later that year at the PGA in Atlanta.
This year, he missed the cut in both the Masters and U.S. Open, and tied for 80th ' out of 83 to make the cut ' at Muirfield.
'That'd be the ultimate,' he said about winning a second major. 'I wouldn't think coming into this week that it was looking too good; certainly my form hasn't been great. But that's the way I play. Any given week I show up and I hit three or four good iron shots in a row and make some putts, I can get hot, get going.'
Leonard and Goosen have both fared better since their major triumphs.
Since winning the 1997 British Open, Leonard lost in a playoff to Paul Lawrie in the 1999 British, and has finished in the top 20 in all three majors this season. He also won the '99 Players Championship.
Goosen, the 2001 U.S. Open champion, finished second this year at Augusta and tied for eighth at Muirfield.
Beem, on the other hand, is making just his fourth career major appearance, and first of the season. He has two missed cuts and tie for 70th (1999 PGA) in his three previous starts.
'I didnt come into this tournament expecting anything. Im just as surprised as you all that Im sitting here, Beem told the media. What Im not surprised is that Im playing well. I know Im good, I know Ive got some game, but at the same time this is a major championship and I havent really done anything in majors yet, so Im pleasantly surprised.
As is Funk, who is also making his first major start of the season. The 46-year-old has only two top-10 finishes in 36 prior majors played.
Full-field scores from the 84th PGA Championship