Graeme McDowell extends advantage in Shanghai

Graeme McDowell has shot 12 birdies in his two rounds in Shanghai

Graeme McDowell shot a second consecutive round of 67 for a three-shot lead at the halfway stage of the WGC-HSBC Champions event in Shanghai.

The 35-year-old Northern Irishman picked up two early birdies to seize control and then had two more birdies on the back nine for a 10-under total.

England's Ian Poulter is his nearest challenger after birdies at four of his last five holes.

Bubba Watson is another shot back after twice chipping in from off the green.

McDowell led by two shots after Thursday's opening round and extended his advantage with birdies at the second and third for the second day in a row. He also managed a birdie at the eighth where he had one of his two bogeys on Thursday.

"It wasn't my best ball-striking round but I hung in there and I'm right where I want to be going into the weekend," he said.

"The putter was fairly hot today but I didn't play as well as I did yesterday; I missed a lot more fairways, which is a big key on this golf course. You must find fairways to have a chance out there. I got lucky a couple of times and I made some good saves."

Meanwhile, Patrick Reed has apologised after using foul and homophobic language on the opening day of the event.

The 24-year-old Ryder Cup player was heard on TV swearing at himself after missing a putt on the first hole.

"At the level I'm playing nowadays you can't have outbursts and unfortunately I did and it happened to be on camera," he said after his second round.

"I made a stupid error and I am sorry for the words I said. It never should have happened. All I can do is just learn from it and move on.

"I'm young and growing up, I had temper issues, on and off the golf course. I live and die through every shot.

"I love the game so much, and I expect perfection, but no one is ever going to be perfect in this game. It's just one of those things that I have to learn how to deal with. It got the best of me this week."