GULLANE, United Kingdom (AFP) - Justin Rose put himself into prime position to successfully defend his Scottish Open crown with a second straight round of 66 at Gullane on Friday.

The 34-year-old English golfer went out in 31 before parring his way down the relatively tougher back nine on the par-70 course, which is a composite of the No. 1 and 2 courses on the East Lothian links.

That left him at eight under for the tournament and the joint clubhouse leader alongside Ireland's Shane Lowry, who had identical back-to-back 66s and Sweden's Johan Carlsson who added a 67 to a first round of 65.

No player has ever retained the Scottish Open title and, were Rose to achieve that feat on Sunday, it would underline his position among the favourites at St Andrews in the absence of injured world No. 1 Rory McIlroy.

Rose's playing partner Phil Mickelson, who won the 2013 Open just down the road at Muirfield, could only manage one birdie on the front nine and bogeys at 10 and 11 saw him flirting with the projected cut after 77 players broke par on Thursday.

But a run of three straight birdies from the 14th proved to be a timely tonic and he came in with a 68 to stand at three under for the tournament.

Low-scoring was again the order of the day with calm conditions prevailing and the greens soft and receptive.

Sweden's Johan Carlsson was the first to get to eight under after setting out in the first group of the day. He had four birdies and one bogey en route to his 67.

"It was good. It was solid. It was a bit less wind today," he said. "Eight under after two rounds on this course, I'm happy with that."

First-round leader Thorbjorn Olesen of Denmark, who had a 63 on Thursday, got off to a steady start with four pars to start his round, leaving him at seven under.