Naomi Osaka starts US Open title defense with win
(CNN) - Despite an up-and-down performance, Naomi Osaka's US Open title defense is underway in New York. "I don't think I've ever been this nervous in my life," Osaka said to ESPN on court after the win. The roller coaster continued in the second set, with Osaka saving three set points to make it 5-5. Osaka is looking to become first woman to defend a US Open title since Serena Williams won three in a row from 2012 to 2014. In January when she won the Australian Open, Osaka became the first woman to win her second consecutive major after winning her first since Jennifer Capriati did so in 2001 (Australian Open followed by the French Open).