Daniel Berger stormed to the top of the FedEx St. Jude Classic leaderboard with the lowest score of the week, a six-under-par 64 in Friday's second round, though the ominous figure of golfing heavyweight Phil Mickelson was in hot pursuit. American Berger, the PGA Tour's rookie of the year last season after recording two second placings among his 13 top-25 finishes, jumped three shots clear of his closest pursuers at the TPC Southwind in Memphis with a nine-under halfway total of 131. Little-known American Tom Hoge (69) was alone in second, with Mickelson, a five-times major winner who next week will head to Oakmont searching for a first US Open victory after a record six runner-up spots, joint third on five-under after a 65. Equal third with Mickelson were fellow Americans Brooks Koepka (65) and long-hitting Dustin Johnson, who got to eight under before dropping three shots in his last two holes for a 69. Johnson, the 2012 champion, bogeyed the 17th after bunkering his approach before running up a double at the last, where he three-putted from seven feet. Berger, whose father Jay was head coach of the 2012 US Olympic tennis team, was delighted to go bogey-free after scrambling well while relying on a red-hot putter. "My speed control has been great and on the greens, I feel like I am just at home," said the 23-year-old from Florida. "I love the Bermuda (grass) and I don't even read grain here." Henderson shares lead Canadian teenager Brooke Henderson held off a host of challengers at the Women's PGA Championship Friday to seize a share of the halfway lead on the difficult tree-lined Sahalee Country Club course. The 18-year-old Canuck is tied with Lee Mi-rim of South Korea at two-under par 140 as just five golfers in the 156 player field have managed sub-par rounds after the first two rounds. First round leader Henderson fired a two-over 73 and at one point she had a three-shot lead on the field at the Seattle, Washington-area golf course. American Gerina Piller also took a brief one-shot lead at one point but bogeyed three of her first five holes on the back nine. She bounced back with a pair of birdies down the stretch and also finished with a two-under 69. Lee birdied the par-four, 425-yard 12th hole to move past Henderson by a stroke. Then Lee slipped up with a bogey on the final hole to finish at two-under 69, tied in third place with three others. On Friday, just four players shot sub-par rounds. Piller sits in a three-way tie for third with world number one Lydia Ko, New Zealand, and Brittany Lincicone at one-under 141. Lombard shares Austria lead South Africa's Zander Lombard shared the halfway lead of the Austrian Open with France's Gregory Bourdy on Friday despite back-to-back bogeys on the back nine. Lombard, who began the day three shots off the overnight lead held by Spanish rookie Adrian Otaegui, is at seven under-par with Bourdy whose score of 69 saw him set the clubhouse target earlier in the day. Lombard fired four birdies in his opening six holes to climb to the top of the leaderboard and parred each of the final five holes to finish his round in 70. France's Gary Stal sits one shot behind the leaders on six under after carding five birdies, two bogeys and a double bogey on his way to a 71. Spain's Borja Virto is a further shot back on five under, while Otaegui is in a group on four-under. Defending champion Chris Wood posted a second successive 71 to move to two-under.