Rory McIlroy and Jordan Spieth set the clubhouse target on day two of the Masters Tournament but Patrick Reed and Marc Leishman were on the charge at Augusta National.
On another day of tough scoring in Georgia, Spieth battled to a 74 while McIlroy carded a 71 with both men laying down the marker at four under.
Australian Leishman sat a shot ahead of them after turning in 33, while Reed led the way at six under with four birdies in his first seven holes.
Reed's playing partner Charley Hoffman was at four under, a shot clear of Henrik Stenson who was level par for the day through seven.
Louis Oosthuizen, Rickie Fowler and Tony Finau were then in the clubhouse at two under.
Overnight leader Spieth got off to a nightmare start, sending his tee-shot right into the crowd and he could not make it onto the fairway with his second which was well back. His third failed to reach the green and when he could not get up and down, his two-shot lead had evaporated already.
He was replaced at the top of the leaderboard by - among others - McIlroy, who had a roller coaster start.
The Northern Irishman bogeyed the first but holed a brilliant 30-foot right-to-lefter on the second and when he hit a big drive and chipped to four feet on the next he was four under.
He would then bogey the fourth and at that point, there was an eight-way tie for the lead.
McIlroy then bogeyed the sixth and Spieth's woes continued as he missed the green with his approach to the seventh and dropped a fourth shot of the day.
Nobody had managed to break away midway through the day, meaning that players who were yet to tee off shared the lead at three under but when the later starters did tee-off, the field began to open up.
Leishman began the day at two under but when he holed a 17-foot left-to-righter on the first, took advantage of the par five second and then chipped up to tap-in range on the third, he had burst ahead.
He was soon caught and passed by Reed, however, who had a birdie-birdie-birdie start of his own.
He holed a 26-footer on the first, made an excellent up-and-down from the sand on the second and then made the most of the short third to hit the front.
He bogeyed the next and the leading pack began to bunch again as McIlroy broke a run of six pars by taking advantage of the 13th and then holed a 27-footer on the next to sit just one back.
Spieth also capitalised on the par five and when he did the same on the 15th, he was just a shot off the lead.
Leishman made a wonderful par save from the trees on the seventh to stay in the lead but Reed went past him with a 13-foot birdie on the seventh.
South African Oosthuizen fired a second consecutive 71, while Fowler and Finau had rounds of 72 and 74 respectively.
Jon Rahm fired the lowest round of the day so far with a 68 to sit at one under, while Tiger Woods was four over at the turn and fighting to make the cut.
