WTA roundup: Nao Hibino upsets defending champ in Prague
Japan's Nao Hibino upset No. 2 seed and defending champion Barboura Krejcikova of the Czech Republic, rallying for a 3-6, 7-6 (5), 6-3 second-round win on Thursday at the Prague Open.Ranked No. 251 in the world, Hibino saved 15 of 22 break…