Argentine Daniel Vancsik and India's Shamim Khan shot superb five-under-par 67s to emerge as unlikely first round leaders on the opening day of the Johnnie Walker Classic on Thursday.

Vancsik, 31, who recorded his maiden European Tour win last year, sank an eagle on the par-five ninth before rolling in three birdies on the back nine.

Khan took advantage of a familiar course as he sank five birdies in a bogey-free round to join Vancsik one shot ahead of the field at the event sanctioned by the European, Asian and Australasian Tours.

World number five Adam Scott was among 11 players who shot 68s for tied third at the par-72 DLF Golf and Country Club in ideal conditions.

"I'm very pleased how I'm playing," the 27-year-old Scott told reporters. "There was one bad shot, I'm happy."

That slip-up led to a double-bogey five on the 16th to drop him off the joint lead before Scott birdied the penultimate hole.

Unheralded Khan gave Indian golf a further boost following compatriot Shivshankar Chowrasia's victory at this month's inaugural Indian Masters.

"The lines aren't too difficult to read," the 29-year-old said. "You have to adjust to it. I took only 24 putts today."

Vancsik credited his sound approach shots.

"The course is really tough and I was perfect with my tee shots," he said. "I had so many chances for birdies and made a few of them which was nice."

India's Jeev Milkha Singh [Images], the 2006 Asia number one, led by one shot with three holes left but bogeyed the next two after finding water on the 16th before saving par from the greenside bunker on the final 18th hole for 68.

Fiji's three-times major winner Vijay Singh [Images] was unhappy with his two-under 70 while eight-times European number one Colin Montgomerie of Britain struggled to post a two-over 74.

"It's very disappointing," Singh told reporters. "I hit the ball really well but didn't putt well. There were too many loose shots, I must say, five or six."

World number 24 Ian Poulter had three double-bogeys in four holes for a four-over 76, his game sharply contrasting with the dazzling golden shirt and shiny trousers he was wearing.

"Maybe he should dress more soberly," joked Vijay Singh, his playing partner.