Swedish pair joined by Lafeber while Parry leads Yorkshire bid

Both men carded eight-under-par rounds of 64 on the Oceanico Victoria course to lead alongside Dutchman Maarten Lafeber. Another Swede, Alexander Noren, was a shot further back, with Finland's Mikko Ilonen. David Horsey was the best-placed Englishman on six-under, alongside veteran Irishman Paul McGinley.

John Parry, from Harrogate, led the Yorkshire challenge with an opening round of 69, while Hull's Richard Finch and Malton's Simon Dyson were a shot further back.

Karlsson and Edfors both covered the Oceanico Victoria course in unblemished rounds including eight birdies.

Karlsson was a model of consistency after starting his round on the 10th, picking up birdies on his first, the 12th, the 16th and the 17th.

He was equally efficient coming back, picking up shots at two, three, four and six.

Edfors did much of his good work in his back nine with five birdies to add to the three he produced on the way out.

Lafeber might have held the lead on his own but for a double bogey on the par-four 18th, which ruined an impressive round including nine birdies.

After birdies on his opening three holes the Dutchman had seemingly lost the momentum in his round when he shot a six at the 18th.

But the 35-year-old recovered impressively as he added a further six birdies on his inward nine to take a deserved share of the lead.

Of Europe's Ryder Cup heroes, England's Ross Fisher and Edoardo Molinari were best placed after shooting four-under-par rounds of 68.