Iga Swiatek survived a major scare as she came from a set and a break down to beat Jule Niemeier and set up a US Open quarter-final with Jessica Pegula.
The world number one looked to be in a real spot of bother against the German ranked 107 places below her, but Niemeier could not maintain her blistering start and Swiatek claimed a 2-6 6-4 6-0 victory.
Swiatek initially looked a shadow of the player who had not lost a set in the first week, with Niemeier's power and unpredictability causing the Pole no end of issues.
Niemeier was immediately a break up and had no problem consolidating before eventually getting another to lead 5-2.
So underwhelming was Swiatek that Niemeier could even afford three double-faults in the final game of the opener as the German impressively took a first-set lead.
After a bathroom break, Swiatek returned with greater purpose but was still lacking ruthlessness; she inexplicably missed a forehand on break point at 1-0 up in the second, and then she stuck a simple volley into the net a few minutes later to find herself a break down.
That was the first of seven breaks in a second set defined by poor serving, but Swiatek was just slightly better than her opponent, with successive breaks giving her the edge in a rollercoaster encounter.
From there, Niemeier barely registered as a threat due to her wastefulness, recording four double-faults and 14 unforced errors to Swiatek's zero and one respectively in the decider as the latter bageled her opponent.
Data slam: Iga's in Pole position
Believe it or not, this is the first time Swiatek has reached the last eight of the US Open, losing in the second round in 2019, the third in 2020 and the fourth in 2021.
She has continued to progress, with her win on Monday making her the first Polish woman to reach the quarter-finals at Flushing Meadows.
Swiatek – 2/2
Niemeier – 5/13
Swiatek – 19/31
Niemeier – 24/45
BREAK POINTS WON
Swiatek – 7/13
Niemeier – 5/12