Qualifier Bellis, 18, stuns Pliskova in Qatar

   CiCi Bellis achieved two more milestones today in her meteoric rise on the WTA tour.
   The 18-year-old qualifier, who was born in San Francisco and raised in nearby Atherton, stunned defending champion Karolina Pliskova, ranked and seeded fifth, 7-6 (4), 6-3 to reach the quarterfinals of the Qatar Total Open in Doha.
   It was Bellis' first victory over a top-five player and former world No. 1.
   "This was huge for me," Bellis, the youngest player in the top 50 by almost two years at No. 48, crowed in her on-court interview. "I think I played a really good match and just tried to track down as many balls as I could. Obviously, I've watched her play for many years, and she's one of my idols, for sure. I'm just really happy I was able to get through it."
   Bellis, the WTA Newcomer of the Year in 2017, recorded her third victory over a top-10 player. She defeated Agnieszka Radwanska and Svetlana Kuznetsova last year when they were ranked No. 6 and No. 8, respectively.
   Add Bellis' win over Petra Kvitova in the Bank of the West Classic quarterfinals at Stanford last August, and she has beaten three former world No. 2s, along with Radwanska and Kuznetsova.
   Also, Bellis has knocked off the last two U.S. Open runners-up in the past two days. Pliskova lost to Angelique Kerber at Flushing Meadows in 2016 in a virtual replay of the 2015 Stanford final. On Wednesday, Bellis ousted 12th-seeded Madison Keys, who fell to Sloane Stephens in last year's U.S. Open after winning the Stanford title earlier in the summer.
   Pliskova missed the Czech Republic's 3-1 victory over Switzerland in Prague in the first round of the Fed Cup last weekend with stomach flu and complained of fatigue against Bellis.
   Bellis avenged a 6-1, 6-1 loss to Pliskova in the second round at Brisbane in the first week of the year.
   "When I played her in Brisbane, she killed me, and I was super nervous before that match," Bellis said of their only previous meeting. "It was the start of the year. It was my second match of the year, and she was playing really well there.
   "I knew I had to be super on top of it from the first point today, and that's what my team and I discussed. From the first point, I had to be 100 percent rather than kind of get into the match and take a few games. So I think that was a big part of it."
   Bellis is scheduled to meet Simona Halep, ranked and seeded second, for the first time on Friday after the 4:30 a.m. (PST) match between fourth-seeded Garbine Muguruza and seventh-seeded Caroline Garcia.
   Halep remains bothered by a sprained ankle suffered during her march to last month's Australian Open final, in which she lost to Caroline Wozniacki 7-6 (2), 3-6, 6-4.