Golf-Berger leads in Memphis, Mickelson four back (Reuters)

June 10 (Reuters) - 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 U.S. Open victory after a record six…