Cough won't halt US golfer Johnson World No.21 Dustin Johnson shook off a lingering cough to make a solid start to the $2 million Perth International golf tournament at Lake Karrinyup. Johnson shot a three-under-par 69 on Thursday to put himself within striking distance of the leaders, while defending champion Bo van Pelt was one stroke further behind. Sweden's Peter Hedblom is the clubhouse leader at four-under, while Australian Dimitrios Papadatos is also at four-under with one hole left to play. Johnson was forced to cancel a scheduled media conference on Tuesday after arriving in Australia with a cold. The 29-year-old was feeling much better by Thursday, but still had to contend with a cough throughout his round. I'm fine. I'm feeling way better than I was," Johnson said. I've just got a little bit of a cough which is OK. I'm back to where I feel good enough to play good golf. Johnson was satisfied with his round, which included five birdies and three bogeys. "It wasn't too bad," the high-profile American said. I missed a couple of short putts but, other than that, I hit it pretty well. The golf course is good. I think it's fun to play. But the greens are really tricky. They are really firm and fast. You've got to be careful where you hit the ball on our second shots. You don't want too many downhill putts because it's hard to stop the ball. If you miss the green in the wrong side, you're dead. Australian Nick O'Hern is also in the hunt after a three-under 69. "I played the Pro-Am yesterday and never made one birdie and thought it was going to be quite difficult," O'Hern said. But I managed to make seven today, so they came in bunches.