Osaka fights off Zheng in tricky San Jose opener

Former World No.1 Naomi Osaka was made to work for her first round win at the Mubadala Silicon Valley Classic, overcoming Qinwen Zheng in a late-night encounter on Tuesday.

Osaka fought past a dip in form in the second set to record a 6-4 3-6 6-1 victory, showing shades of the fighting spirit that saw her rise to the top of the tennis world.

The first set saw the Japanese superstar win 14 of 16 points behind her first serve, an act that allowed her to save three break points. A single break of Zheng's serve was enough for Osaka to establish a one-set lead.

However, Zheng would not be deterred so easily as the Chinese star looked even better on serve in the second set. The World No.51 did not face a break point, capitalizing on temporary loss of momentum by Osaka to earn a break and take the match to a deciding set.

With everything on the line, it was Osaka who obtained an early break and never looked back. The four-time Grand Slam champion employed her big serve to save both break points faced, and relied on her thunderous groundstrokes to overpower Zheng from the baseline. After securing a second break, Osaka closed out the match in just over two hours.