Japan's Hiroshi Iwata equalled the lowest round in major championship history as Rory McIlroy recorded a second consecutive one-under-par 71 at the US PGA Championship. Padraig Harrington, Shane Lowry, Graeme McDowell and Darren Clarke all missed the cut.
Iwata fired an eagle, eight birdies and one bogey to card the 27th round of 63 in the majors, the 34-year-old covering the back nine at Whistling Straits in just 29 to improve on his opening 77 by 14 shots.
That gave the world number 102 a halfway total of four under par, three behind clubhouse leader David Lingmerth - who added a 70 to his opening 67 - and two behind Jordan Spieth, who is attempting to become just the third player after Ben Hogan and Tiger Woods to win three majors in a season.
Spieth began the day five shots off the pace and tipping playing partner Rory McIlroy to make a move up the leaderboard, but it was the Masters and US Open champion who took advantage of the ideal conditions to shoot 67.
Defending champion McIlroy double bogeyed the 18th hole, his ninth of the day, and chipped in for an eagle on the second in an eventful second consecutive 71 to finish two under par.
South Africa's George Coetzee was two shots off the lead after a superb 65, the 29-year-old having needed a birdie on the 18th for a 63 but taking five after finding sand off the tee.
Coetzee, who has won twice on the European Tour this season, had missed the cut in his last three events and carded an opening 74, but fired seven birdies, an eagle and two bogeys to card the lowest round of the week before Iwata's heroics.
Here comes Rory! 💪 http://t.co/rEujbAEkxs
— The European Tour (@EuropeanTour) August 14, 2015
After starting from the 10th, Spieth and McIlroy were both one under par for the day after eight holes before Spieth holed out from a greenside bunker on the 18th for birdie and McIlroy mishit two chips from left of the green for a double bogey.
It was the 16th time this season Spieth had chipped in and the 22-year-old said: "It's arguably the best of the year given the position it was in."
After making the cut in the US PGA for the first time, Spieth joked: "We are freerolling now. I'm just happy to be back in contention and position. If I'd had a bit of a lull today it would have been too hard to make up."
Spieth added three more birdies on the back nine while McIlroy chipped in for an eagle on the second and birdied the sixth, but bogeyed the seventh after failing to get up and down from left of the green.
"I felt like tee to green I hit the ball pretty well, I'm probably just not as sharp with the short game as I would like to be," said McIlroy, who is playing his first tournament since the US Open in June after seven weeks out due to an ankle ligament injury suffered while playing football with friends.
"It was good to get the two shots back on the second that I dropped on 18 and I gave myself good chances on the third and fifth, but did not take them. There's plenty of chances out there and if I can convert a few hopefully there is a low score in me."
Australians Jason Day and Matt Jones (both -9) were battling England's Justin Rose (eight under) for the lead when play was suspended due to the threat of lightning.
Dustin Johnson - the overnight leader - was static on six under par overall when play stopped just before midnight Irish time.
Graeme McDowell was one under for the day and level par overall through 12 before a disastrous finishing sequence of bogey, double-bogey, bogey for 76 left him five over and three off the projected cut mark of two over.
Padraig Harrington improved on his opening round by five shots to card a 71 but after five birdies and four bogeys on his front nine the Dubliner couldn't pick up the extra shots he needed and just missed out on three over.
WGC Bridgestone champion Shane Lowry also finished one shot outside the cut mark despite shooting an excellent 69. Five birdies and two bogeys in his opening 14 holes brought participation in the weekend tantalisingly close but a bogey on the par-four eighth (his 17th) ended his chances.
Former Open champion Darren Clarke endured an even more miserable second round, triple bogeying the eighth as he added an 81 to his opening 78 to finish 15 over par.
