DONGGUAN  - Adam Scott and Louis Oosthuizen closed in blistering style Thursday to snatch a one-shot advantage on seven-under-par 65 at the top of a star-studded WGC-HSBC Champions leaderboard.Australia’s Scott, wielding his broomstick putter, closed birdie, birdie, eagle, while Oosthuizen, the 2010 British Open champion, birdied two of his last three to cap a bogey-free first round at southern China’s Mission Hills. The stunning finishes put them one stroke ahead of four-time Major-winner Phil Mickelson, US Masters champion Bubba Watson, Shane Lowry and Peter Hanson after a low-scoring first day with a constantly evolving lead.Dustin Johnson and Thailand’s Prom Meesawat were two shots off the lead, while Luke Donald and defending champion Martin Kaymer were in a group three back in the $7 million event at the sprawling resort’s par-72 Olazabal Course.Ryder Cup hero Ian Poulter was four off the pace with 69 and Lee Westwood finished strongly to score 70, level with British Open champion Ernie Els. Scott, who can still add lustre to a season which will be remembered for his collapse at the British Open, provided the day’s highlight over his last three holes, capped by his eagle putt from 10 feet on the par-five ninth.“I had a good start and a fast finish so it was a solid day that all of a sudden turned into a really good day,” Scott said. “But I hit a lot of good shots, and they ended up finishing close on the last couple of holes and I took advantage of that.” Oosthuizen, who was tied sixth at last week’s BMW Masters, behind Hanson, said he hadn’t realised how many birdies were available until red numbers started flooding the scoreboard. He birdied all five of the par-fives.“I don’t think I saw a really low number out there but once you look at the leaderboard and see the guys are firing it up, all of a sudden you started seeing birdies,” said the South African. Mickelson mirrored Scott by picking up two shots on his last hole, the par-five ninth, in one of 12 eagles on the day to gain a temporary lead.“It was a great way to finish with an eagle. I was hoping just to make birdie on the last hole,” Mickelson said. The American, relaxed and chatty on a bright, fresh morning, began on the par-four 10th with a 25-foot uphill putt for birdie and then escaped from a bunker to go two under through his first two holes.On the spectacular par-five 15th, Mickelson fired over the lake into another bunker — but flopped out to within six feet to reach three under par and share the early lead. He also birdied the par-five third, but his round was transformed by his last hole, the par-five ninth, when he was on the green with two sweeps of his three-wood and holed out from 15 feet for an eagle.“I think the reason I was so calm today was I drove the ball extremely well and hit (nearly) every fairway. I missed one fairway by two yards, the par-five three, and I still made birdie,” Mickelson said.