Phil Mickelson's lead was cut to just one shot at The Open Championship at Royal Troon, on a wet and windy day in Ayreshire.
The American finished the day two under par at -10, just a shot ahead of Sweden's Henrik Stenson on -9. Fellow Scandinavian Søren Kjeldsen finished tied on -7 with Keegan Bradley also on the same score.
Defending champion Zach Johnson continues steady progress in his bid to retain the Claret Jug, five shots off the lead.
Mickelson out early in Ayreshire
With memories of Thursday's opening round of glorious skies and a stillness of wind still fresh, Troon was set to show its' ugly side as the forecast took a decidedly bleak turn.
Before the rather inclement conditions swung through the West coast of Scotland, the opening groups had a chance to carry on their momentum of yesterday evening.
As some of the last trios to take on the course yesterday, the names at the head of the leaderboard were out early. Picking up on -8, Phil Mickelson started solidly before birdieing the 4th as he did yesterday, then again picking up strokes on 7 and at The Postage Stamp, with a glorious iron off the tee. Mickelson reached the turn on 32.
The 46 year-old stumbled somewhat on the back nine, dropping his first shots of the week at 12 and 15, either side of holeing a clutch putt on the 14th as the rain and wind arrived at Troon. A steady if unspectacular 5, 3, 4 concluded his Second round with the clubhouse lead - where he stayed during the duration on Friday.
Stenson shrugs off conditions and shoots 65
Henrik Stenson began resolutely in his opening round but after Mickelson's near record-breaking turn, the Swede was five off the summit. Stenson however made Friday his, picking up four birdies in the first seven holes.
Stenson found trouble on the 9th with a bogey but continued his progress a-pace, at 10, 13 and 16 to record a low of 65. As Mickelson hit the buffers somewhat, the Swede fancied in some corner to lift the trophy crept up and finshed -6 for the day, just one shot off the lead.
Fellow Scandinavian Søren Kjeldsen also made his Second Round move. The Dane scored an unblemished 68 and added three to his score overnight at -7. He is joined by 2011 PGA Champion Keegan Bradley. The 30 year-old American also shot a 68, set fair for his final 36 holes.
Zach Johnson clings onto his crown, five shots off Mickelson but after his surging finish last year at St. Andrews, Johnson will still fancy his chances.
McIlroy, Watson and Spieth flounder in treacherous conditions
Elsewhere, as the elements took a hugely bleak turn shortly after 5.30pm, the bigger names down the leaderboard struggled in vain to inject some belief into their tournament.
The Ayreshire weather had other ideas. With Rory McIlroy's round on a knife-edge at -4, the Northern Irishman once more dropped vital strokes at key moments, with more trouble to come.
Together with Bubba Watson and Justin Rose, the quartet were hounded shortly after six o'clock as monsoon conditions descended on the course making shots almost unplayable. McIlroy battled to stay under par - finishing well off the pace at -2 - whereas the other three fought to stay not just afloat, but to make the cut.
Spieth and Watson both ended on +4 on the cusp of missing the weekend. After Danny Willett also finished on four over, the champion at Augusta was left to sweat. However, all three were projected to squeeze in late on Friday evening. World number one Jason Day finished with a 70 at +1 with his hopes of a first Claret Jug vanishing.