RIO GRANDE, March 9, 2012 (AFP) - Jones, never better than fourth in a US PGA event, followed his first-round 66 strongly to stand on 11-under 133 after 36 holes with American George McNeill -- who had shared the lead with Jones after round one -- next on 136.
Jones, who started at the 10th hole, birdied the par-4 14th and par-5 18th, then birdied both par-5s on the front side, the second and fifth holes, and closed with a birdie at the ninth.
"I've been putting really well and chipping unbelievably well," Jones said.
The Aussie has struggled to keep his playing rights but has been able to take advantage of his opportunities to stay on tour.
"I've been improving my putting which is the big difference this week," Jones said. "My putting was terrible last year and that's why I'm in this situation but I actually fixed it last week and it's coming along nicely."
Japan's Ryo Ishikawa and American Todd Hamilton shared third on 137. Ishikawa fired a second-round 67 while Hamilton shot 69.
The 20-year-old Japanese sensation started on the back nine and birdied three holes in a row -- including the 14th, par-5 15th and par-3 16th -- before taking his lone bogey of the day at the 18th.
Ishikawa birdied the par-5 second and par-4 fourth and added another at the par-3 eighth to put himself among the leaders entering the weekend.
"Short game was very good and approach shots and putting," Ishikawa said. "Everything went well. That resulted in birdies and some nice par saves. So the short game was the key thing."
Ishikawa entered the event in hopes of earning a secure spot on the US PGA circuit but also to boost his rankings in hopes of qualifying for the Masters, a move rendered moot when he received a special invitation to the Masters on Monday.
"It is, of course, a relief that I got the invitation from the Masters committee," Ishikawa said. "But when I play a tournament, I concentrate on the tournament. So I don't think about anything else.
"Yes I feel relieved, but when I play a tournament, I will play to win."
Sharing fifth on 138 were Argentina's Andres Romero and Americans Daniel Summerhays, Boo Weekley, Roberto Castro and Kevin Stadler.
Another stroke off the pace were Zimbabwe's Brendon de Jonge, Sweden's Henrik Stenson, Canada's Graham DeLaet, American J.J. Killeen and England's Brian Davis.
Scores on Friday after the second round of the $3.5 million Puerto Rico Open (par 72, USA unless noted):
133 - Matt Jones (AUS) 66-67
136 - George McNeill 66-70
137 - Ryo Ishikawa (JPN) 70-67, Todd Hamilton 68-69
138 - Andres Romero (ARG) 71-67, Daniel Summerhays 68-70, Roberto Castro 69-69, Boo Weekley 70-68, Kevin Stadler 69-69
139 - Brendon de Jonge (ZIM) 69-70, Graham DeLaet (CAN) 69-70, Brian Davis (ENG) 69-70, Henrik Stenson (SWE) 70-69, J.J. Killeen 70-69
140 - Roland Thatcher 69-71, Vaughn Taylor 70-70, William McGirt 71-69, Danny Lee (NZL) 70-70, Richard S. Johnson (SWE) 71-69, Gavin Coles (AUS) 69-71, Lee Janzen 69-71, Ben Curtis 67-73, Kevin Kisner 68-72
141 - Jerry Kelly 71-70, Will Claxton 69-72, Stephen Gangluff 74-67, Jeff Overton 68-73, Shaun Micheel 69-72, Erik Compton 71-70, Scott Brown 69-72