Key Biscayne, Florida: 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."
Sloane Stephens won an all-American match on the stadium court, converting five of six break-point chances to beat No. 17 Madison Keys 6-4, 6-2. It was the first meeting between the two Fed Cup teammates, and Keys teared up near the end of her loss.
"I just kind of let the emotions get to me," the 20-year-old Keys said. "It's like you're having a really terrible day, but my terrible day is in front of hundreds of people and then broadcast on TV. That's not always fun."
No. 2-seeded Rafael Nadal, showing no ill effects from an ankle injury suffered in practice Monday, defeated fellow Spaniard Nicolas Almagro 6-4, 6-2.
"I am well," Nadal said. "The day after, I had pain, but after two days I improved 50 percent. It's not limiting my movements."
Others advancing in the women's draw included No. 3 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 beat American Donald Young 6-4, 6-2. Other men's winners included No. 7 Stan Wawrinka, 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.
No. 10 Feliciano Lopez was eliminated by Dominic Thiem, 7-6 (4), 4-6, 6-3. Four-time champion Novak Djokovic lost in doubles and plays his opening singles match Saturday night.
"Hopefully I can have another great week in Miami," Djokovic said. "Some of my best tennis I have played here in these courts."
Two-time champion Victoria Azarenka reached the third round by beating No. 20 Jelena Jankovic 6-1, 6-1. Azarenka faced 13 break points and saved them all.
"I stayed composed," Azarenka said. "I was very sure what I had to do, and I was really executing that."
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."