Sixth seed Tanvi was easily upset by unseeded American Beiwen Zhang in straight games, who clinched the Tier IV title at Centre Sportif. The favourite in the final, the 20-year-old Indian lost 12-21, 12-21 in 26 minutes flat Sunday.
Earlier in the day, the Mumbai girl beat Japan's seventh seed Yuka Kusunose 16-21, 21-14, 21-19 in one hour and two minutes in the semi-finals.
Elsewhere, Russian top seeds Vitalij Durkin and Nina Vislova beat unseeded pair Indian Pranaav Jerry Chopra and K. Maneesha 21-15, 21-11 in 25 minutes in the mixed doubles semi-final.
While French pair Lucas Corvee and Brice Leverdez upset Indian top seeds Chopra and Akshay Dewalkar 21-18, 21-16 in 30 minutes in the men's doubles semifinal.