Adelaide, Jan 3 : Australian wildcard Priscilla Hon registered the biggest win in her career so far, upsetting two-time Wimbledon champion Petra Kvitova to reach the second round of the Adelaide International, here on Monday. Hon recovered from a set to beat the 17th-ranked Czech 6-7(4), 7-5, 6-2, her first-ever victory over a top-40 opponent. It capped a magnificent day for the host nation as another Australian Ajla Tomljanovic joined Hon in the second round with a 6-4 7-6(5) win over British Heather Watson. Earlier, Two-time Grand Slam semi-finalist Maria Sakkari defeated Slovenia's Tamara Zidansek 6-2, 0-6, 6-4 to reach the last 16. The world No.6 Sakkari, who is the third seed in the draw, struggled behind her second serve where she won just 42% of points and hit 20 less winners than her opponent (25-45). Nevertheless, she managed to battle back to seal victory by breaking Zidansek in the final game of their match. But it was Hon who hogged the limelight on Monday in Adelaide. The world No.263 played with clarity and countered Kvitova's power with heavy shot-making of her own. "It doesn't really feel real right now. Will probably sink in later. But I'm just so happy right now. I can't even explain how much I've been waiting for this moment," said Hon, who trailed Kvitova 4-2 in the second set. Pretty proud of how I held up at the end. I've been working really hard at that and staying calm, and obviously against the top players they don't give it to you, so you've got to really work hard for it," she said. Sakkari struggled for consistency and rhythm against Zidansek, battling for more than two hours to see off her opponent in the match. She showed no reaction when she broke Zidansek at love to seal victory, admitting on court afterward that she "didn't feel great" and that "it wasn't a good match from my side". "I knew that it was going to be a very tough match, because she had a great season last year and she has beaten some very good opponents the last couple of seasons," Sakkari told adelaideinternational.com.au. "I didn't play my best tennis, but I found ways to win, and found the right tactic to win, which is what I take from the match, and that's what I'll try to do in my second match as well." Also through to the second round is world No.100 Kaja Juvan who defeated France's Chloé Paquet 6-4, 6-2. She will next play world No.2 Aryna Sabalenka who received a bye in the first round. This year's Adelaide International features no fewer than five of the world's top 10 players. /IANS