Bellis beats Mertens in Dubai, will face Muguruza

   Elise Mertens became CiCi Bellis' latest high-profile victim today.
   And it wasn't close.
   Bellis, an 18-year-old wild card who was born in San Francisco and raised in nearby Atherton, dispatched Mertens, an Australian Open semifinalist last month, 6-3, 6-3 in the opening round of the Dubai (United Arab Emirates) Duty Free Tennis Championships.
   Mertens, a Belgian ranked 21st, won only 29 percent of the points on her second serve (8 of 28) versus 50 percent (13 of 26) for Bellis, ranked 41st, in their first career meeting.
   Bellis will face Garbine Muguruza, ranked third and seeded second, for the first time in Wednesday's late match at about 9 a.m. PST. Muguruza, who won the French Open in 2016 and Wimbledon last year, received a first-round bye.
   A victory over Muguruza would be the biggest of Bellis' career, topping her win over No. 5 Karolina Pliskova in the third round at Doha last week. It also would be Bellis' fourth triumph over a Grand Slam singles champion after her victories over Jelena Ostapenko (who later won the French Open), Petra Kvitova and Svetlana Kuznetsova.
   ATP World Tour -- In a battle of California natives, 20-year-old Taylor Fritz edged fourth seed and 2016 champion Sam Querrey 2-6, 6-3, 7-6 (4) in the first round of the Delray Beach (Fla.) Open. 
   The 30-year-old Querrey, originally from San Francisco, played two days after he lost to Kevin Anderson, also in a third-set tiebreaker, in the final of the inaugural New York Open in Uniondale, N.Y.