New York - Britain's world number 97 Johanna Konta shocked Wimbledon runner-up Garbine Muguruza in the longest women's match in US Open history on Thursday.
Konta won in 3 hours 23 minutes with her 7-6 (7/4), 6-7 (4/7), 6-2 triumph eclipsing by seven minutes the previous record set in 2011 when Samantha Stosur defeated Nadia Petrova.
"I am so tired. I think both of us were," said Konta, who hit 10 aces and 36 winners in a match played in fierce 30-degree heat.
"She didn't play her best but she is an incredible fighter and always brings a top-10 mentality.
"I came out to give my best. I was humble enough to know that she could beat me so I fought and chased down every ball."
Sydney-born Konta has now won 15 matches in a row since Wimbledon and goes on to tackle German 18th seed Andrea Petkovic for a place in the last 16.
Muguruza committed 59 unforced errors and had to save 15 of 19 break points.
Ninth seeded Muguruza became the fifth top-10 seed to crash out of this year's tournament before the third round.
The 21-year-old Spaniard joins first round victims, sixth seed Lucie Safarova, seventh-seeded Ana Ivanovic, number eight Karolina Pliskova and 10th-ranked Carla Suarez Navarro on the sidelines.
With Maria Sharapova having withdrawn through injury on the eve of the season's concluding Grand Slam, the women's draw was down to its bare bones.