Britain's US Open underdog Johanna Konta clinched another shock win at the US Open as she knocked out 18th seed Andrea Petkovic to reach the last 16.
Ranked 97th in the world, Konta sits 79 spots lower than her German opponent but the British number two continued her remarkable run in Flushing Meadows with a 7-6 (7/2) 6-3 victory.
It means Konta extends an impressive winning streak to 16 consecutive matches and she will now meet two-time major champion Petra Kvitova for a place in the quarter-finals.
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Beating the Czech represents a seismic task but if achieved, Konta would become the first British female to reach the last eight of a major tournament since Jo Durie at Wimbledon in 1984.
"It was tough, even if she wasn't at her best she is still one of the best competitors on the tour," Konta said of her match against Petkovic.
"I'm just really happy I made it through in the end. I've been playing a good level of tennis all year but it's always a confidence boost when you get to compete against the best players in the world."
Arriving in New York with only one grand slam victory in her career, Konta now has three in a week including the second round scalp of ninth seed Garbine Muguruza, who made the Wimbledon final in June.
Wimbledon was the scene of Konta's last defeat, coming against Maria Sharapova in the first round, and the 24-year-old is likely to climb into the world's top 60 regardless of the outcome against Kvitova.
British number one Heather Watson, due to rise slightly from number 61, is certainly within her sights while the prize for making the US Open fourth round stands at 213,575 US dollars (?140,848) - the largest haul of Konta's career.
The Briton looked nervous early on, falling 2-0 down after two unfortunate net chords, but she soon found her rhythm to move 4-3 ahead.
Petkovic was rattled by her opponent's forceful hitting and resolute defence, with the German showing her frustration as she picked up a code violation for whacking her racquet into the court.
Both players struggled to hold serve but Konta found her groove in the tie-break, winning seven points in a row to take a deserved one-set lead.
A beleaguered Petkovic struggled to respond and after the first game of the second she informed the umpire she felt unwell and wanted treatment.
By the time the medic arrived she was 3-0 down as Konta showed no mercy, driving her backhand into the corners to excellent effect.
She spurned three match points when serving at 5-1, and then two more at 5-3, to revive memories of former matches when she made a habit of wobbling away from winning positions.
Konta, however, is a player transformed and she finally converted her sixth to confirm victory in one hour and 56 minutes.
Victory over Petra Kvitova in the last 16 will make Konta the first British woman to reach the quarter-finals of a Grand Slam singles tournament since Jo Durie at Wimbledon in 1984.