Louis Oosthuizen, of South Africa, looks for his ball in the water off the 15th green during the second round of the Masters golf tournament Friday, April 11, 2014, in Augusta, Ga. (AP Photo/Matt Slocum)

Augusta, United States - Louis Oosthuizen eagled the 13th hole at Augusta National on Friday to take a share of the lead at four under in the second round of the Masters.

The 2010 British Open champion started the day one off the pace set by Bill Haas, who was not due out untill later in the afternoon.

But he fell back with bogeys at four and seven before rebounding with a birdie at eight and the eagle at 13.

Level with him on four under were Kevin Stadler through five holes and Jonas Blixt of Sweden after four.

Bubba Watson, the champion two years ago, reached that mark too, but a bogey at nine pegged him back.

Australian March Leishman briefly held the overall lead at five under after three opening birdies, but back-to-back birdies at four and five hauled him back on another day of clear blue skies and warm sunshine at Augusta National.

Much of the day's focus though was on the late starters with leader Haas due out at 1715 GMT.

Defending champion Adam Scott, also one stroke back from overnight leader Jay Haas, was in the penultimate grouping at 17.48 GMT with Rory McIlroy (71) the last man to tee-off in the company of Jordan Spieth (71) and Patrick Reed (73).