Taipei, Aug. 10 (CNA) Taiwanese tennis veteran Hsieh Su-wei (謝淑薇) and her Latvian partner Jelena Ostapenko advanced to the women's doubles semifinals at the WTA 1000 Toronto Masters on Sunday, edging past an unseeded pairing in straight sets. The last event they played together before this week's tournament in Toronto was the Qatar TotalEnergies Open in February. The duo carried their momentum into the second set, breaking serve twice to race to a 4-0 advantage. Tauson and Li mounted a comeback to narrow the gap to 5-4, but Hsieh and Ostapenko held their nerve in the 10th game to close out the match. The win sends Hsieh and Ostapenko into the semifinals, where they will face third-seeded Sara Errani of Italy and Nicole Melichar-Martinez of the United States for a place in the final.