KEY BISCAYNE, Fla. (AP) -- Precocious amateur CiCi Bellis says she's ready to take on the best of the pros -- Serena Williams.
Bellis, a 15-year-old American who made a big splash at last year's U.S. Open, advanced Friday to a potential third-round match against Williams by beating Zarina Diyas 6-2, 6-1.
Williams was scheduled to play a second-round match Friday night against Monica Niculescu. Bellis was already relishing the chance to take on the 19-time Grand Slam champion.
"It's going to be really fun," Bellis said. "I have nothing to lose, so I'm just going to play my game and see what happens."
Others advancing in the women's draw included No. 3-seeded Simona Halep, the titlist last week at Indian Wells. She won 6-4, 2-6, 6-1 against wild card Nicole Vaidisova, a two-time Grand Slam semifinalist mounting a comeback from two shoulder operations.
Two-time champion Andy Murray defeated American Donald Young 6-4, 6-2. Other men's winners included No. 8 Tomas Berdych and No. 25 Bernard Tomic. American Sam Querrey had 19 aces but lost to No. 15 Kevin Anderson 6-7 (5), 7-6 (3), 6-4.
Two-time champion Victoria Azarenka reached the third round by beating No. 20 Jelena Jankovic 6-1, 6-1. Jankovic had 13 break-point chances and converted none.
Bellis became the youngest player to win a match at the U.S. Open since 1996 when she upset 12th-seeded Dominika Cibulkova last August. Suddenly a celebrity, Bellis then lost to Diyas in the second round.
She avenged that defeat Friday with much less fanfare.
"This one I think I played a lot smarter," Bellis said. "At the U.S. Open I was really like caught up in all the kind of hype that was going on. But this one I was just really focused and played my game. I think I did what I needed to do to win really well."
The Californian has yet to turn pro, and the Miami Open is her biggest tournament since the U.S. Open. She made the draw as a wild card and played Friday on remote Court 9, but she'll be on the stadium court Sunday if she faces Williams, who has won Key Biscayne a record seven times.
Intimidating? Bellis says no.
"We are all in the same tournament, so we are all kind of at this level," she said. "You can't really think about who you're playing. It's just a ball that's coming back on the other side of the court. You just have to go out and not think about that stuff and just play your game. That's what I'm planning to do."