UPDATE 2-Golf-Day gets up off deck to climb into share of Masters lead

Jason Day was barely able to walk when the Masters began but he fired a five-under 67 on Friday to climb into a share of the second-round clubhouse lead alongside Francesco Molinari and Brooks Koepka. Still walking gingerly after throwing out his back bending over to kiss his daughter on the practice range on Thursday, a determined Day worked his way around an overcast Augusta National turning in a near flawless scorecard, with six birdies and a single bogey at the par-three 12th.

Day has endured back issues for much of his career, and only a month ago pulled out after less than seven holes at the Arnold Palmer Invitational with what he described as a disc tear. The battling Australian had looked poised for an early exit when he stretched out on the turf at the second tee in the opening round to receive treatment.

In contrast to Day's determined second-round effort, Molinari was as smooth as Italian silk, carding an error-free 67 for his best round in eight Masters that put the British Open champion in contention for a Green Jacket to go along with the Claret Jug he hoisted last year. "Didn't really get in trouble at any point. Just played solid," said Molinari, whose first taste of the Masters came in 2006 when he caddied for brother Edoardo. "Really happy the way I played.

"But yeah, obviously still a long, long way to go, so let's see what we'll be able to do on the weekend." Koepka, who had shared a one-shot overnight lead with Bryson DeChambeau, had a far more adventurous day. After a bogey-free opening round, Koepka had two in his opening six holes on Friday, along with a double at the second to drop him down the leaderboard.

Yet the twice U.S. Open champion was able to regain his composure, steadying himself with six straight pars from the ninth followed by birdies at 15 and 18 to salvage a 71 to join the clubhouse lead at seven-under 137. Justin Harding was also on seven-under with holes to play.

DeChambeau, who had opened up a two-shot lead early in the second round, completely unravelled on the back nine with a double bogey at the 10th and bogeys at the 12th and 16th, slumping to a three-over 75. World number one Justin Rose, who opened with a 75, had another difficult afternoon. He signed for a one-over 73 and will have to wait to see if his four-over midway total will be enough to get him in under the cut line.

Rory McIlroy, who arrived at the year's first major as golf's hottest player and chasing a career grand slam, sat on one-under with nine holes to play. (Editing by Pritha Sarkar and Toby Davis)