Melbourne - Adam Scott blew a big lead at the Australian Masters on Friday after a torrid back nine allowed Peter Wilson to catch him at the top of the leaderboard.
The Australian world number 12 extended his one-shot overnight lead to as many as five strokes midway through day two at par-71 Huntingdale in Melbourne.
But a double bogey on the 10th, a bogey on the 13th and another dropped shot on the 18th changed the complexion for Scott, the 2012 and 2013 Australian Masters champion.
He eventually signed for a one-under 70 to be at eight-under 134, level with fellow Australian Wilson, who has shot two successive rounds of 67.
One stroke back in outright third was Matt Guyatt (69), who has twice finished in the top 11 in the past three years of this tournament.
Scott only found one of five fairways with his wayward driver.
"I had a lovely start, playing really solid and then a couple of loose shots on the back nine and I was just grinding to get it into the clubhouse," he said.
"That's the way it goes.
"It was a shame because I felt like I didn't do too much too bad but the driver cost me three or four shots.
"I just couldn't get it on the fairway to take advantage of the par fives."
There are 18 players within five shots of Scott and Wilson on a crowded leaderboard.
Brett Rumford shot the day's low round of 64 to be tied for fourth with American George McNeill.
Among those to miss the halfway cut were Belgian Nicolas Colsaerts and Australian Presidents Cup team member Steven Bowditch, the second-highest ranked player in the field.
Scores after the second round of the Australian Masters at the par-71 Huntingdale golf course in Melbourne on Friday (Australia unless noted):
134 - Peter Wilson 67-67, Adam Scott 64-70
135 - Matthew69-66
136 - George McNeill (USA) 70-66, Brett Rumford 72-64
137 - Nathan Holman 71-66, John Senden 69-68, Mathew Goggin 67-70, Andrew Evans 68-69
138 - Matthew Millar 71-67, Ashley Hall 71-67
139 - Stephen Allan 70-69, Stephen Leaney 69-70, Daniel Fox 65-74, Josh Cabban 72-67, Alistair Presnell 68-71, Bryson DeChambeau (USA) 69-70
140 - Zach Murray 69-71, Nick O'Hern 70-70, Michael Wright 72-68, Michael Sim 71-69, Peter Senior 70-70
142 - Pan Cheng-Tsung (TPE) 70-72
147 - David Klein (GER) 74-73
149 - Nicolas Colsaerts (BEL) 75-74
161 - Petr Dedek (CZE) 79-82
Final cut made at +3 (145)