The 32-player field features 16 players from the LPGA Tour and 16 players from the Japan LPGA Tour (JLPGA). The players were ranked by their current position on each tour's money list and the top players from the LPGA met the bottom players from the JLPGA and vice versa.
Sorenstam was defeated by Chieko Amanuma by a score of 2 and 1, while Pak was bounced by Takayo Bandoh, 1-up.
The first round could not be completed Thursday as the final match between Rachel Teske and Yu-Chen Huang was suspended due to darkness. The pair was even through 27 holes and will meet at the 10th tee at 7:30 PM ET to decide their match.
Sorenstam and Amanuma, who met in the round's first match, halved the first five holes before Amanuma won the sixth to go 1-up. Amanuma won the ninth to go 2-up at the turn but Sorenstam won the par-5 10th to cut the lead to 1-up.
Amanuma struck back at the next hole to go 2-up again and extended her lead to 3-up with a win on the 13th hole. Sorenstam tried to make a move by winning the 16th to fall 2-down but when the players halved 17, Amanuma pulled off the incredible upset.
Pak and Bandoh were even through five holes but Bandoh took the advantage with two wins in her next three holes. Pak won the ninth to cut the deficit to 1-down but Bandoh captured the 12th hole to reclaim her 2-up edge.
The duo halved the next four holes and Pak won No. 17 to fall 1-down with one to play. The pair halved the 18th at Narita Golf Club to pull off the first round's other big upset.
In other action Thursday, Rosie Jones handled Mihoko Takahashi, 5 and 4, while Hee-Won Han of the LPGA Tour needed 20 holes to polish off Woo-Soon Ko of the JLPGA. Laura Diaz won the last two holes Thursday to defeat Kyoko Ono, 1-up.
Midori Yoneyama of the JLPGA bested the LPGA's third-ranked Mi Hyun Kim, 1-up. Lorie Kane trounced Orie Fujino, 7 and 6, in the round's sixth match and Kelly Robbins dismissed Kasumi Fujii, 3 and 2.
Cristie Kerr squeaked out a 1-up victory over Kaori Higo and Kerr's Solheim Cup teammate, Michele Redman, also scored a 1-up win in her match against Ok-Hee Ku.
Catriona Matthew needed 19 holes before she dispatched Toshimi Kimura. Carin Koch and Karrie Webb of the LPGA Tour both notched 3 and 2 wins in their first round matches, with Koch bettering Ikuyo Shiotani and Webb defeating Hsiu-Feng Tseng.
Grace Park of the LPGA had little trouble with Mikino Kubo in the first round. Park won, 4 and, and Yuri Fudoh followed with a 3 and win over American Beth Bauer.