Zandvoort, Netherlands (My Sportsbook) - Paul McGinley and Gary Orr opened with six-under 64s Thursday to share the lead after the first round of the KLM Open.

Defending champion Darren Clarke is one stroke off the lead after opening with a 65. He was joined in third place at Kennemer Golf & Country Club by Peter Lawrie, Matthew Millar and Jorge Campillo.

The first round was completed despite a one-hour weather delay.

McGinley played the back nine first on Thursday and reeled off four consecutive birdies from the 12th to jump up the leaderboard. From there, he parred his next four holes around the turn.

The Irishman converted an eagle at the par-five second move into the lead at six-under.

McGinley, who finished second to Clarke last year, came right back with a birdie on the par-three third. The four-time winner on the European Tour tripped to a bogey on the eighth to fall out of the solo lead.

"The game is moving very much into a power game, so it's refreshing to play an old-fashioned type of course," McGinley stated. "My season's been flat. I've not played well enough, no excuses, and I need to do better."

Orr parred his first six holes from the first, before rolling in back-to-back birdie chances from the seventh. He parred three straight before dropping his second shot within four feet at the 12th. Orr sank that to move to minus-four.

The 42-year-old moved within one of the lead thanks to a birdie on the 14th. Orr joined McGinley at minus-six with a birdie on the par-three 17th.

"I've been playing pretty well lately, just not making enough putts," Orr admitted. "I've thrown a few bad rounds in here and there, but I've done a bit of work over the past few weeks, and it seems to be working. I've been trying to find a bit more consistency, and hopefully we're getting there."

Former British Open champion Paul Lawrie opened with a four-under 66. He shares seventh place with Phillip Price, Jamie Donaldson, Bradley Dredge, Kenneth Ferrie, Ignacio Garrido, Peter Hedblom, Wade Ormsby, Callum Macaulay and Shane Lowry.

European Ryder Cup captain Colin Montgomerie struggled to a six-over 76. He is tied for 138th place and is six strokes over the current cut line.