LONDON - South Korea's Ryu So-Yeon stretched her lead to five strokes after firing a six-under par 66 in Friday's second round of the LPGA Canadian Women's Open. Ninth-ranked Ryu, the 2011 US Women's Open champion whose only other LPGA title came at the 2012 Toledo Classic, opened by matching course record with a 63 and followed up with another solid effort to stand on 15-under 129. "After I shot nine-under, six-under is not that great, but still it's a really great score and I made a lot of great putts," Ryu said. "I had a bogey-free round two days in a row, so I feel really great about that. That's my goal. I aim for a bogey-free round all four days." South Korean Choi Na-Yeon, American Danielle Kang and Sweden's Anna Nordqvist shared second on 134 with Cristie Kerr another stroke adrift.–AFP