Novikov loses to 6-foot-11 Opelka in 150K Challenger

   Reilly Opelka, a 6-foot-11 (2.11-meter) wild card from Palm Coast, Fla., defeated qualifier Dennis Novikov, a San Jose product, 6-4, 6-4 today to reach the quarterfinals of the $150,000 Oracle Challenger Series in Newport Beach, Calif.
   Opelka, 20, blasted 19 aces in the match. Novikov had beaten top-seeded Kei Nishikori in the first round. Nishikori, the 2014 U.S. Open runner-up, was playing his first match since suffering a right wrist injury in August.
   Bradley Klahn, the 2010 NCAA singles champion from Stanford, beat fellow American Mitchell Krueger 6-3, 1-6, 6-4.
   Klahn, who's rebounding from his second back operation, will meet 18-year-ld Miomir Kecmanovic of Serbia. Kecmanovic ousted second-seeded Frances Tiafoe in the opening round and another top U.S. prospect, Stefan Kozlov, in the second round.
   On the women's side, Nicole Gibbs of Venice in the Los Angeles area held off Anna Schmiedlova of Slovakia 7-6 (6), 6-4.
   Gibbs, the 2012 and 2013 NCAA singles champion from Stanford, will play seventh-seeded Ajla Tomljanovic of Croatia. Tomljanovic, a former top-50 player rebounding from right shoulder surgery, dispatched Canada's Carol Zhao, the 2016 NCAA singles runner-up from -- you guessed it -- Stanford, 6-1, 6-3.
   Tomljanovic withdrew from the final of the $60,000 Sacramento Challenger against 15-year-old U.S. phenom Amanda Anisimova last July with a right shoulder injury.