Sania Mirza crashed out in the first round of the MPS Group Championships.
The unseeded Indian went down to seventh seed Alona Bondarenko of Ukraine 4-6, 3-6 in Florida on Monday.
Alona next meet her sister, Kateryna, who defeated Barbora Zahlavova Strycova 7-6(2), 6-2.
Meanwhile, 14-year-old American Madison Keys won on her WTA Tour debut with a 7-5, 6-4 first round win over Russian Alla Kudryavtseva.
Madison fought back from 2-5 down in the opening set to upset Alla, ranked 81 in the world, and set up a possible second round meeting with Russian top seed Nadia Petrova. Madison, who made her professional debut at the $25,000 Challenger at Fort Walton Beach this month, becomes one of the youngest players to win a WTA match.
American Mary Joe Fernandez holds the record, notching her first victory at 13 years seven months, according to the WTA.