KOHLER, Wis. -- Play was suspended late Friday afternoon as the second round of the 97th PGA Championship continued at Whistling Straits.
The round will be completed beginning at 7 a.m. CT on Saturday and the third round in the final major championship of the year will follow.
Conditions were hot and muggy throughout the day before a line of thunderstorms developed in the area and led to a weather warning around 4:30 p.m CDT. Play continued until 5:28 p.m., when flashes of lightning began to appear over the course, located on the shore of Lake Michigan about an hour north of Milwaukee.
David Lingmerth of Sweden was the leader in the clubhouse when play was halted at 7 under par, but Australians Jason Day and Matt Jones were atop the leaderboard at 9 under and Justin Rose of England was one behind. Day had played 14 holes, Jones was through 12 and Rose had one hole remaining.
Lingmerth started the day in second place, a stroke behind first-round leader Dustin Johnson. Lingmerth double-bogeyed the par-3 No. 7, bogeyed Nos. 8 and 9 and also 11 and 15 but finished his round with eight birdies -- including a 35-footer at 18 -- for a 2-under 70.
Johnson, who shot a 66 Thursday, started in the afternoon and dropped one shot to stand at 5 under through 14 holes.
"The wind was down a little bit, but it was a beautiful day," said Lingmerth, who teed off in the morning. "The greens are at a firms right now where you can throw some darts in there at a few of the holes, so the conditions are pretty good."
Tied at 7 under with Lingmerth were Harris English and Tony Finau. English was 3 under for the day through 15 holes and Finau was 6 under for his round after 13 holes.
Jordan Spieth, attempting to win a third major this year, shot a 5-under 67, putting him at 6 under for the tournament. He bogeyed once, on the par-3 12th hole, but had six birdies during the round.
"In order to keep shooting rounds like today, I'm going to need to drive the ball better and make a few more putts, which are really the two keys to this weekend." Spieth said. "It's just going to get more challenging with pin locations and firmness of greens."
Spieth was grouped again with world No. 1 Rory McIlroy, who shot 71 for the second straight day and was at 2 under.
Hiroshi Iwata of Japan became the 27th player in major championship history to shoot a 63. The 35-year-old had an eagle and eight birdies against a lone bogey in his 9-under round. Of the 26 players who have previously shot a round of 63 in a major championship, five have gone on to win.
"When I came here, I was thinking just to make my golf better and better," Iwata, who shot a 77 Thursday, said through an interpreter. "And on Sunday, I could probably be in the top 10."
NOTES: Green Bay Packers quarterback and reigning NFL Most Valuable Player Aaron Rodgers was on hand for round two, a morning after his team opened the exhibition season with a 22-11 victory at New England. ... Through two rounds, Jordan Spieth is 43 under in major tournament play this season, 20 strokes better than any other player. ... Thursday leader Dustin Johnson is a combined 37 under in the first two rounds of his last six majors, but 6 over in the final two rounds of the tournaments. ... Some tournament caddies sported Caddyshack-themed socks Friday, an effort to raise awareness for St. Jude's Children's Research Hospital. ... Alex Cejka of Germany withdrew before the start of the second round because of an ankle injury.