Sugiyama played mixed doubles at two events: the French & the US Open. At Roland Garros, playing with Mirnyi, she lost in the first round. At the US Open, she partnered with Ullyett. The duo reached the quarterfinals, losing to eventual champions Hantuchová and Bhupathi. Entering the Doha with an 0–5 singles record, she managed to beat wildcard Selima Sfar 6–3, 6–3. In the second round, she surprisingly upset Myskina 7–6, 6–7, 6–4, needing several match points to close the match out. In her quarterfinal match against Julia Schruff, she had a comfortable 6–3, 6–2 win. She lost in the semifinal, in an epic match against Nadia Petrova, 1–6, 6–7. At 0–4 in the second, she won five consecutive games to 5–4. She won the doubles title with Hantuchová, defeating Yan and Zheng in the semifinal 6–3, 3–6, 6–3, and Li Ting and Sun Tiantian 6–4, 6–4 in the final.