Saina Nehwal today beat the reigning world champion Carolina Marin to retain the women's singles title at the Syed Modi Grand Prix Gold Badminton tournament in Lucknow. World No. 3 Saina scraped past the seventh-ranked Spaniard 19-21, 25-23, 21-16. With this win, Saina maintained her 100 percent win against Carolina in three career meetings. Top seed Kidambi Srikanth takes on third seed Parupalli Kashyap in an all-Indian men's singles final later today.