Australia’s 25th seed fought off four match points before succumbing 7-6 (8-6) 4-6 7-6 (7-5) to big-hitting American Shelby Rogers in a three-hour, 33-minute epic at Flushing Meadows.

The gruelling encounter lasted 10 minutes longer than Johanna Konta’s victory over Garbine Muguruza in New York two years ago.

“It was always going to be me. I was always going to be in the records for the longest match somewhere, so I’m not surprised,” Gavrilova said.

Riding high on a six-match hardcourt winning streak after landing her maiden WTA crown in new Haven on Sunday, Gavrilova was gutted to have bowed out of the season’s final grand slam.

“It feels like I’ve played for three-and-a-half hours for nothing,” the gritty baseliner said.

“I don’t know what my emotions are right now.I’m pretty disappointed.”

In truth, the 23-year-old showcased her signature fighting spirit throughout a high-quality, rollercoaster and historic encounter that featured 11 service breaks, 76 winners, 111 unforced errors, a 90-minute deciding set and a warm embrace between the two exhausted combatants at the net.

The junior champion at Flushing Meadows in 2010, Gavrilova was on the back foot from the outset.

Only her incredible and relentless retrieving kept her in the sapping contest.

“I’m proud of the way I hung in there mentally. I didn’t play my best tennis,” Gavrilova said.

Three times she fought back from a break down to force the first-set tiebreaker.

She successfully challenged a line call to save one set point but eventually yielded to Rogers’ power play to fall a set behind.

Gavrilova rallied from a set and a service break down in the second to force the decider.

Alas, in a major turning point, Gavrilova blew two break-point chances that would have handed her a 5-2 lead in the third set, and then failed to finish Rogers off after leading in the deciding tiebreak.

Despite the defeat, Moscow-born Gavrilova has taken a giant stride over the American summer towards securing a place in the season-ending WTA Elite Trophy in China.

The event will feature players ranked between ninth and 19th in the rankings, and Gavrilova will likely depart New York as the new world No.17.

“That was my goal – to qualify for Zhuhai,” she said.

Gavrilova’s exit leaves Ashleigh Barty as Australia’s last women’s singles hope at Flushing Meadows.

Barty plays American Sloane Stephens on Saturday morning for a place in the fourth round.

Meanwhile, Australian tennis battler John Millman has continued his blazing US Open run to charge into the third round and earn himself the opportunity of a lifetime.

Australia’s last man standing backed up his upset defeat of Nick Kyrgios with a 6-1 7-6 (7-1) 6-1 dismissal of Tunisia’s Malek Jaziri to make the last 32 in New York for the first time.

Millman next plays either German Philipp Kohlschreiber or Colombian Santiago Giraldo – both unseeded – for a $US144,000 ($A181,080) pay day and coveted spot in the second week of the season’s final grand slam event.

Contesting the Open on an injury-protected ranking, Millman’s progression is a huge result for the Queenslander in his latest comeback from surgery.

The 28-year-old, who has endured two shoulder reconstructions, a groin operation and countless other injuries in a career constantly stalled, arrived as the No.235 in the world.

He is now projected to soar at least 60 spots up the rankings, as well as earn a cheque for $US144,000 – more than doubling his season earnings – or possibly more.

Attempting to become the lowest-ranked player since 1985 to make the last 16 in New York, Millman showed no physical weakness from his four-set win over Kyrgios.

He struck 27 winners and broke Jaziri seven times in a victory that took exactly two hours.

“I knew that I would be playing in less than 24 hours time and that is a tough back up, especially with my body the way it is. It was unchartered waters for me,” Millman said.

“I haven’t really done the best-of-five back-up in less than 24 hours, so I was probably slightly apprehensive yesterday as to how my body would pull up.

“I am extremely happy with the level I am at and how I am hitting the ball.

“I am starting to play the big points better, which is really important when you are coming back from injury.

“Because when you have lacked that match experience, it is really difficult to be super clinical.”

With Kyrgios under a fitness cloud, Thanasi Kokkinakis losing in the opening round and Jordan Thompson exiting in round two, Millman is also giving Australian Davis Cup captain Lleyton Hewitt food for thought ahead of this month’s semi-final in Belgium.

-AAP