NEW YORK, NY, USA - Coming into the US Open, Japan's Nao Hibino had lost her first seven straight Grand Slam openers - and in CiCi Bellis, she would face a prodigious 18-year-old with the home crowd behind her whom she had already lost to twice.

No matter: the World No.80, a two-time finalist this year in Kuala Lumpur and Nanchang, was still able to retrieve a 3-5 final set deficit to finally score that elusive debut victory to the tune of 6-3, 4-6, 7-5. In a finely balanced match, Hibino's winner count inched just ahead of Bellis's, 25 to 23, while she kept her unforced errors a hair lower, 38 to 44.

Elsewhere, there was a 100% success rate for mothers on court as Evgeniya Rodina and Tatjana Maria both delivered straight-sets victories. World No.89 Rodina won her first Slam match of 2017 to make her way into her third straight US Open second round with a 7-6(2), 6-1 win over Eugenie Bouchard; the Canadian World No.76 fell away after losing a tight first set, racking up 46 unforced errors as the Russian kept her game tight and focused. Maria, meanwhile, took just 62 minutes to dispose of 18-year-old wildcard Ashley Kratzer 6-1, 6-1. 

Evgeniya Rodina is silhouetted against Arthur Ashe Stadium during her first-round win over Eugenie Bouchard (Getty)

Sticking to the formbook, there were a number of contrasting victories for seeded players. No.20 CoCo Vandeweghe was made to fight for a 2-6, 6-3, 6-4 win over compatriot Alison Riske, the tenth edition of the American duo's nine-year rivalry. No.17 Elena Vesnina also had a countrywoman to quell - and for the second Slam in a row, she ended 18-year-old Anna Blinkova's run through qualifying, this time by a 6-1, 6-3 scoreline.

No.27 Zhang Shuai overcame the challenge of Sabine Lisicki 6-7(4), 6-3, 6-0 in the German's fourth tournament back from injury, and last week's champion in New Haven Daria Gavrilova, the No.25 seed, took exactly an hour to move past Allie Kiick, the qualifier making a heartwarming comeback from skin cancer and multiple knee surgeries, 6-2, 6-1.

A handful of seeds fell late in the day.  No.11 Dominika Cibulkova, just off a run to the Connecticut Open final in New Haven, lost to one of the hottest players of the summer, Sloane Stephens, by the score of 6-2, 5-7, 6-3.  Stephens, who has seen her ranking rise over 800 spots in the last month due to back-to-back semifinals at the Rogers Cup and the Western & Southern Open, now faces another rising player, Ashleigh Barty, in the third round.  Barty, of Australia, took out Aliaksandra Sasnovich of Belarus, 6-1, 7-6(7).  

Meanwhile, in delayed first round play, No.14 seed Kristina Mladenovic's summer slump continued, with an opening loss to Monica Niculescu, 6-3, 6-2. It was hardly the only upset in postponed first-rounders, as Christina McHale tripped up No.19 seed Anastasia Pavlyuchenkova, 3-6, 6-3, 6-2, and Lucie Safarova ousted No.26 seed Anett Kontaveit, 6-7(5), 6-1, 6-4. 

Competitive second round victories went to No.18 seed Caroline Garcia, who rallied for a 4-6, 6-3, 6-0 win over Ekaterina Alexandrova, and Carla Suárez Navarro, who squeaked by No.29 seed Mirjana Lucic-Baroni, 4-6, 7-6(4), 6-2.

Also, two of China's top players lost their second round matches in the evening, as Donna Vekic blitzed No.22 seed Peng Shuai, 6-0, 6-2, and No.30 seed Julia Goerges cruised past Zheng Saisai, 6-2, 6-1.