South Korea’s So Yeon Ryu 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 the London Hunt and Country Club course record with a 63 and followed up with another solid effort to stand on 15-under-par 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.

South Korean Na Yeon Choi, American Danielle Kang and Sweden’s Anna Nordqvist shared second 10-under-par with American Cristie Kerr another stroke adrift.

Lindsey Wright is the best-placed Australian at eight under in a tie for sixth.