Li Na of China returns to Daniela Hantuchova of Slovakia at the China Open tennis tournament in Beijing, Sept 29, 2013. [Photo/Xinhua]

BEIJING - World number one Serena Williams and home-favored Li Na both powered into second round with easy wins while third seed Agnieszka Radwanska was given an early scare at the China Open on Sunday.

Williams, a former China Open champion, was barely troubled by her Russian opponent Elena Vesnina, needing only one hour and 25 minutes to wrap up the opening round win.

"She serves really well, I just had to be ready for everything, " said Williams, who broke Vesnina five times in the match.

The American had a stellar season by winning nine titles, including two Grand Slams, and she has secured the WTA yearend No 1 with still two months' competitions remaining on the calendar.

"I definitely feel like I have a target. Whether I'm No 1 or No 10, I feel like my opponents lift their game against me. I think it's good. And I also think that's one of the reasons it helped me to be able to develop as well," added Williams.

Serena Williams of the US celebrates after defeating Elena Vesnina of Russia in their women's singles first round match at the China Open tennis tournament in Beijing, Sept 29, 2013. [Photo/Xinhua]