NorCal's Tsoi upends No. 2 seed in National Winter 18s

   Unseeded Dylan Tsoi of El Dorado Hills, Calif., in the Sacramento area surprised No. 2 seed Bjorn Swenson, a University of Michigan signee from North Oaks, Minn., 6-7 (3), 7-5, 7-5 today in the fourth round of the boys 18s in the USTA National Winter Championships.

   Tsoi, a high school junior, is scheduled to play No. 18 seed Lucas Brown of Plano, Texas, in Saturday's quarterfinals in Orlando, Fla. Brown beat No. 22 seed Noah Hernandez of Hinsdale, Ill., 6-4, 6-1.

   Also reaching the quarters were No. 14 seed Emon van Loben Sels of Sacramento in the boys 18s, No. 2 seed Mitchell Lee of Oakland, Calif., in the boys 16s and No. 4 seed Natasha Rajaram of Cupertino in the San Francisco Bay Area in the girls 16s.

   The 14s and 12s in Tucson, Ariz., are behind schedule because of inclement weather, ZooTennis reported.