MELBOURNE, Australia - Home favorite Astra Sharma pulled off an astronomical upset in the first round of Australian Open qualifying, dismissing No.1 seed Vera Zvonareva 6-3, 6-2 in one hour and 11 minutes.

The Russian was coming off one of the best results of her comeback following maternity leave, a semifinal showing in Shenzhen last week that lifted the former World No.2 back inside the Top 100 for the first time since January 2013. However, Zvonareva had been forced to retire with a left hip injury against Alison Riske in their last-four match - and today the 34-year-old had few answers in the face of the 28 winners fired by Sharma, a college tennis star at Vanderbilt University who has put her medical degree on hold in order to go professional.

It's a decision that has paid off so far for the 23-year-old Australian, who won three ITF titles in 2018 out of just 14 tournaments played, finished her first pro season at a career high of World No.225 - and can now boast a first Top 100 win.

The year's first breakthrough sensation, Auckland runner-up Bianca Andreescu, also progressed - although not, perhaps, in the manner that the Canadian would have wanted. Leading the former junior World No.2 Katie Swan 6-1, a back injury struck the Briton, who had to be wheelchaired off court. Thankfully, the 19-year-old's management would later confirm to the press that Swan's issue had been a muscle spasm that had led to "considerable pain at the time but nothing serious".

For 18-year-old Andreescu, who thrilled fans by stunning Caroline Wozniacki, Venus Williams and Hsieh Su-Wei in just her fourth WTA main draw last week, the result will nonetheless be a respite following her physical travails in New Zealand. Up next for the No.4 seed is Greece's Valentini Grammatikopoulou, who defeated Romania's Irina Bara 6-3, 6-2.

Elsewhere, there was a dramatic win for No.5 seed Anhelina Kalinina, who had to save a match point before beating Martina Di Giuseppe 6-4, 2-6, 7-6[10-5] in two hours and seven minutes. The Ukrainian, who turned heads on her Slam debut at the US Open last year when she pushed Sloane Stephens to three sets, moves on to face American Jamie Loeb.

Doubles World No.1 Barbora Krejcikova also sprung an upset, eliminating No.13 seed Marie Bouzkova 6-4, 4-6, 6-4 in an all-Czech derby. Krejcikova, who won her first two Grand Slam doubles trophies at Roland Garros and Wimbledon last year alongside Katerina Siniakova, plays a top-level schedule that has prevented her from focusing on building her singles ranking, currently a modest No.202. The 23-year-old was always one of the most dangerous floaters in the draw, though, as Bouzkova - at a career high of No.120 following her run from qualifying to the Brisbane second round - discovered today.

Yesterday, two of 2018's junior Grand Slam winners - Wimbledon champion Iga Swiatek and US Open victor Wang Xiyu - made winning starts to their first senior major campaigns. Today, though, Australian Open girls' champion Liang En-Shuo failed to join them - although the 18-year-old Chinese Taipei player, ranked No.255 and competing here via wildcard, pushed Bibiane Schoofs hard, leading by a break in the deciding set before falling 6-2, 5-7, 6-4.

Meanwhile, Anna Kalinskaya extended her unbeaten streak in 2019 to six matches with a 6-1, 7-6(14) defeat of Quirine Lemoine. The 20-year-old Russian began the year with a title run in last week's ITF W25 event in Playford; after cruising in the first set, she was forced to save seven set points in an epic second set tiebreak before finally progressing on her fifth match point. Playford runner-up Elena Rybakina, who upset Caroline Garcia to make her maiden WTA quarterfinal in St Petersburg last year, was less successful; the 19-year-old Kazakh fell to No.11 seed Zhu Lin 6-2, 6-4.

There were also wins for Misaki Doi and Kurumi Nara, the pair of Japanese former Grand Slam seeds attempting returns to Top 100 territory this year. No.22 seed Doi eased past Olga Doroshina 6-3, 6-3, while Nara scored an upset over No.32 seed Veronica Cepede Royg 6-2, 7-6(1). Seven-time WTA runner-up Lucie Hradecka's nascent comeback also took another positive step forwards: having upset Olga Danilovic in Brisbane qualifying last week, the 33-year-old World No.532 won her first Grand Slam qualifying match since the 2017 US Open, 6-3, 6-3 over Ekaterine Gorgodze.