Song finished two rounds of stroke play at 4-under 138, edging 13-year-old sensation Michelle Wie by two shots. Wie also carded a 4-under 67 in the second round after posting a 2-over 73 during the first 18 holes.
Rain had been a major factor over the first two days of competition at the Philadelphia Country Club. The first round of match play was scheduled to begin Wednesday, but will now take place Thursday morning.
Song will face Emily Bastel in match play at 7:30 AM (ET). Bastel was one of five to come through a 10-player playoff for the final five spots in the match-play field of 64.
The second round of match play is scheduled for Thursday afternoon and Song could meet her sister, Naree, if both win their first-round matches. Naree finished 33rd in stroke play with a two-round total of 8-over 150.
Wie, meanwhile, will take on Maru Martinez in the opening round of match play on Thursday.
The third round and quarterfinals are slated for Friday, with the semifinals scheduled for Saturday. The 36-hole final is set to take place on Sunday.