KEY BISCAYNE, Fla. - When the ball whizzed past Serena Williams for an ace late in Sunday's match, the subdued crowd suddenly erupted with a roar.
Williams said she was tempted to join the applause. Everyone wanted to see her underage, underdog opponent do better.
Fifteen-year-old Californian CiCi Bellis lasted only 41 minutes against Williams, losing 6-1, 6-1 in the third round at the Miami Open.
"It wasn't like, 'Oh, I'm so happy to win this match,'" said Williams, 33. "It was tough. She's young and her being an American, you want to see people like her do well."
While Williams moved a step closer to her eighth Key Biscayne title, Rafael Nadal again came up short. He was eliminated by fellow Spaniard Fernando Verdasco, 6-4, 2-6, 6-3.
Nadal, who was seeded second, has never won the tournament in 11 appearances. It's the only event he hasn't won in so many tries.
The precocious Bellis made headlines by winning a match at last year's U.S. Open, but she couldn't stay with the world's No. 1 player. Williams won 51 of the 65 points and lost only two points in seven service games.
Bellis managed to smile afterward despite the drubbing.
"I was pretty nervous," she said. "I didn't know how my game would hold up against her, because I have never played her before. Never really seen her in person, just on TV.
"I mean, she's my idol; she's from America; she's No. 1 in the world; she's the best of all time. It's pretty scary playing her."
Williams advanced to Monday's round of 16 against 2006 champion Svetlana Kuznetsova, seeded No. 24. She eliminated No. 13 Angelique Kerber 6-3, 3-6, 6-3.
Nadal beat Verdasco the first 13 times they played but has now lost to him twice in a row. Nadal dealt with several health issues in 2014 and said that while he's fully recovered, he hasn't regained his confidence.
"It's a question of being relaxed enough to play well," the 14-time Grand Slam champion said. "I'm still playing with too much nerves for a lot of moments, in important moments, still playing a little bit anxious in those moments.
"But I'm going to fix it -- I don't know if in one week, in six months, or in one year, but I'm going to do it."
The Key Biscayne draw was already without Roger Federer, who skipped the tournament. Four-time champion Novak Djokovic and two-time champion Andy Murray are now heavy favorites to make the final.
Murray, seeded No. 3, reached the fourth round by beating Santiago Giraldo 6-3, 6-4.
In other women's play, two-time champion Victoria Azarenka lost to No. 15 Flavia Pennetta 7-6 (5), 7-6 (6). Azarenka, mounting a comeback from injuries, was playing at Key Biscayne for the first time since 2012.
No. 3 Simona Halep, who won Indian Wells a week ago, reached the women's fourth round by beating No. 30 Camila Giorgi 6-4, 7-5.
Williams withdrew before the semifinals at Indian Wells, citing an ailing right knee, but hardly had to run against Bellis.
The teenager, who had never played in such a large arena, appeared to be overwhelmed and overpowered from the start. But then at 5-6, she was smaller -- and perhaps younger -- than some of the ballkids.
Williams shared the crowd's subdued mood, forgoing her customary fist pumps and other demonstrative gestures as she blasted winners. She hit 13 to only one by Bellis, who is the world's top-ranked junior and still an amateur.
Their postmatch handshake was brief.
"I just said, 'Good job,' and that's it," Williams said.
"She's really nice," Bellis reported. "I mean, there's not much that you can say, but, you know, whatever."
Williams was already ranked in the top 20 when Bellis was born in 1999, and she drew a blank when asked to recall her first match against a top player, saying it was too long ago.
"I don't remember," Williams said. "I have been playing a little over 10 decades.
"I never played that well at 15 to play professional. I wasn't good enough. So, I mean, CiCi's doing really great."