England's Ian Poulter overcame a bout of food poisoning to birdie the final two holes for a 3-under 68 and a two-stroke lead after the second round of the JBWere Australian Masters on Friday.
Poulter, who woke up feeling ill Friday morning after taking a one-shot lead in the first round, had a 9-under 133 overall at Victoria Golf Club.
Matthew Giles was in second place after a 68, while fellow Australian Ashley Hall was third after a 70.
Top-ranked Luke Donald of England was at 3 under after a 70, while defending champion Stuart Appleby was forced to withdraw due to a painful back injury.
Greg Chalmers, also 3 under after a 70, is trying to become the second player to complete the Australian Triple Crown after winning the Australian Open and Australian PGA Championship last month. Robert Allenby accomplished the feat in 2005.
Poulter overtook the leaders with consecutive birdies on the two closing par-5 holes.
He said the weather over the final two days would be the key for players at the head of the field.
"Wind is the protection for this golf course. If it blows a strong 30 (miles per hour) and they put the pins in tricky positions, the scoring's not really going to go anywhere."
Poulter said he was ill before he drove to the course for the start of the second round.
"I woke up this morning and wasn't good at all," he said. "Must have had something bad to eat unfortunately so I felt a bit weak out there today.
"And it showed. I hit it terrible, got myself out of position a number of times, but my short game was on and I holed a few nice putts so to look back at the round I would have taken that score."
Donald endured an up-and-down day that could have been considerably better. The Englishman got to 4 under early in his round when he made back-to-back birdies at two of the most difficult holes on the course -- the par-4 sixth and short par-3 seventh -- but he found trouble at the eighth and gave back both shots immediately.
Despite his inconsistent round, Donald still thinks he remains a threat.
"I hit a lot of good shots today, but I've been struggling on the greens," he said. "I'm finding it hard to see the line and missing my fair share of chances for birdie.
"Hopefully I'm saving them all for the weekend," he added. "I'm still in a decent position, I just need to get that putter going and get on a roll."
Geoff Ogilvy looked flat early in his round before springing to life at the par-5 ninth with a chip in for eagle from the back of the green.
Four more birdies -- along with one dropped shot -- followed on the back nine for the Victorian as he finished the day tied with Brendan Jones, Nathan Green, Brent McCullough, Kieran Pratt and Lonard at 5 under, four off the pace.
It looked like Lonard was going to finish higher up the leaderboard when he birdied his eighth and ninth holes, the 17th and 18th, to move into a share of the lead at 7 under, but the 44-year-old dropped three shots in a row on his back nine to finish with a 70.
Italian teenager Matteo Manassero fared much better on the second day, with the 18-year-old posting a round of 67 to follow his disastrous 76 on Thursday, while playing partner Robert Allenby carded 17 pars and one birdie to finish with a 70. Both players finished the day tied for 47th at 1 over, one shot ahead of the cut that was made at plus-2.
Notable players that missed the cut included veteran Australians Peter O'Malley and Paul Gow, plus New Zealander Michael Campbell and American Jeff Maggert.