Final frontier for Aussie trio in US Open qualifying

That's all that separates Chris O'Connell, Tristan Schoolkate and Storm Hunter from making the main draw of the US Open.

The Australians' dream of competing in the final tennis grand slam of the year at Flushing Meadows is alive after the men posted straight-sets victories in New York on Wednesday (Thursday AEST) en route to the final qualifying round.

Hunter later advanced with a come-from-behind 4-6 7-6 (8-6) 6-0 win over Korean Yeonwoo Ku.

It was a gutsy effort from the 32-year-old from Queensland, who will now meet Latvian world No.109 and No.4 seed Darja Semenistaja in her final frontier.

Hunter is trying to join Talia Gibson, Maya Joint, Daria Kasatkina, Kimberly Birrell and Ajla Tomjlanovic in the main women's draw.

Priscilla Hon, who like Hunter was involved in the qualifiers, was ousted by Taiwan's Joanna Garland 6-3 6-4.

After one hour and 41 minutes, O'Connell saw off the challenge of Nicolai Budkov Kjaer, winning 7-5 6-4.

The Sydneysider was dominant at the net, winning six from seven points. The world No.105 also excelled in the big plays, allowing the Norwegian to convert just one of 10 break-point opportunities.

In contrast, O'Connell broke serve three times and showed fewer nerves in the high-stakes encounter, making 18 unforced errors to Kjaer's 30.

Now standing in his way is Zsombor Piros, the Hungarian who is seeded 12th and leads their head-to-head 2-1.

Schoolkate was involved in an almighty 6-4 7-6 (8-6) tussle with Seongchan Hong that lasted two hours and five minutes.

In a match marred by 73 unforced errors - Schoolkate made 38 and Hong 35 - the West Australian posted 28 winners to the Korean's 17.

Schoolkate and O'Connell are trying to join fellow Australians Alex de Minaur, James Duckworth, Thanasi Kokkinakis, Rinky Hijikata, Adam Walton and Aleksandar Vukic, all of whom have already qualified.