Suzuki, ranked No. 850 in the world, raced to 4-0 lead in the first set but she failed to sustain her level of performance when Santos, who reached the second round of the Asian Tennis Championships in Uzbekistan last month, stepped up to win the set in 32 minutes.
Suzuki regained her form in the second set, taking a 2-0 lead before Santos, who started to train under former player and now Ateneo coach Randy de Guzman last June, made it, 3-2.
The Japanese tied the count at 3-3 but Santos, also a member of the RP Federation Cup team, swept the next three games to wrap up the match in one hour.
Santos will face the winner between No. 8 Chattida Thimjapo of Thailand and qualifier Lam Po-Kuen of Hong Kong-China who were still playing at presstime.
Earlier, qualifier Diana Julianto of Indonesia used a variety of shots to score a 2-6, 6-1, 6-4 upset win over world’s No. 483 Napaporn Tongsalee of Thailand, the top seed in this event supported by the ITF Grand Slam Development Fund, Wilson balls, Manila Midtown Hotel and Philippine Sports Commission.
Julianto, a quarterfinalist in the $10,000 Mysore event in India last September, will advance against Korean qualifier Lyoo-Suh Hae-sun, who survived Julia Gandia of Spain, 2-6, 7-5, 6-1.
First leg champion Sania Mirza of India needed an extra set to beat Thassha Vitayaviroj of Thailand, 6-0, 2-6, 7-6 (4) and advance against qualifier Kim Kilsdonk of Netherlands, who struggled past sixth seed Sonal Phadke of India, 6-4, 2-6, 6-3.
Second seed Khoo Chin Bee of Malaysia defeated Cassandra Barr of Australia, 6-3, 6-4, to advance against Gabriela Velasco-Andreu of Spain, who beat Megha Vakharia of India, 6-2, 6-2.
Other winners were Wilawan Choptang of Thailand over seventh seed Wang I-ting of Chinese Taipei, 6-3, 6-2, Diana Costa of Portugal over Geeta Manohar of India, 6-2, 6-1, and Dong Yah-hua of China over cramp-stricken third seed Pariyawan Ranatakrong of Thailand, 6-2, 1-0 (ret).