Graeme McDowell was in top form in the second round on Friday

Graeme McDowell holds a two-shot lead at the Ballintine's Championship in South Korea after an eight-under-par 64 in Friday's second round.

The Portrush player moved to 12 under at the halfway stage and two clear of Johan Edfors and Jeev Milka Singh.

Paul McGinley is next best of the Irish on nine under after a 67 while Padraig Harrington shot 65 to go eight under.

Damien McGrane is four under after a 69 but Hollywood's Rory McIlroy is set to miss the cut on three over after a 71.

Interview: Graeme McDowell

High winds brought a two-hour suspension to play and Gary Murphy was three over after 14 holes when play was halted because of poor light.

McDowell, 28, carded six birdies and an eagle three at the 10th in a bogey-free round.

Eight under par, 36 holes to go - I'm well in there Padraig Harrington

He later revealed he had gained some extra help from playing partner Thomas Bjorn who also moved into contention with a 66.

"We've been helping each other out a little bit in and around the greens this week," said McDowell.

"We've been practising together and he gave me a little bit of a bunker-play lesson yesterday and gave me a couple of tips on my putting on Tuesday."

Open champion Harrington was relieved to complete his second round before darkness left the second round uncompleted.

"It made a big difference to get those last couple of holes played," he said. "It was nice to get teed off on 18 and know you were definitely getting finished.

"Eight under par, 36 holes to go - I'm well in there."