PERTH, Australia (AP) _ Denmark's Steen Tinning struggled down the stretch and lost a four-stroke lead Saturday in the third round of the Heineken Classic.

Australia's Nick O'Hearn shot a 3-under par 69 for a three-round total of 204, two strokes ahead of defending champion Michael Campbell of New Zealand, who shot 67.

Tinning (72), Australia's Peter Lonard (66) and first-day leader Dean Robertson of Scotland (68), are tied for third at 207.

Tinning's suffered headaches throughout the round and bogeyed the final two holes.

``I kept getting the headaches after six or seven holes,'' Tinning said. ``My caddie asked if I wanted any pills ... but I decided against it. Towards the end of the round I started feeling worse and worse.''

Greg Norman challenged briefly, but three-putted the 11th hole and finished with a 70, five shots back of O'Hern.

Campbell has moved up the leaderboard over the last two days, and likes his chances.

``I'm only two shots behind, so I've put myself in contention,'' he said. ``Myself and this golf course get on very well, it's incredible how I just love this golf course.''

Gerry Norquist was the top U.S. player, shooting a 68 for a 3-under 213 total. Charles Howell shot a 77 for a 220 total. Robert Floyd, the son of senior star Raymond Floyd, had a 75 for a 219 total.