Great Britain's hopes of United Cup glory came to an end as they were comprehensively beaten in the Sydney city final 4-1 by the USA, who advance to the semi-finals.
During the lunchtime session, Madison Keys got the USA off to a winning start with a 2-6 6-3 6-4 win over Katie Swan before Cameron Norrie continued his strong run by beating Taylor Fritz 6-4 5-7 6-4.
Jessica Pegula restored the USA's slender advantage with a straightforward 6-2 6-0 beating of Harriet Dart, and Tim Henman's team were condemned to defeat when Frances Tiafoe beat Dan Evans 3-6 7-5 6-3.
GB could have still qualified for the semis as the best-performing losing host city finalist, but Pegula and Fritz sent the Brits home after a 6-4 6-4 win over Dart and Evans in the final doubles encounter.
Despite the 134-place difference between them in the WTA rankings, Swan exploded out of the blocks against world number 11 Keys and broke three times in a brilliant first set.
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However, Keys responded in kind, storming into a 3-0 lead in the second set and levelling the match before a hotly-contested third, in which Swan was broken in the fifth game but broke back straight away.
Keys broke once more in the ninth game before converting her second match point, getting the job done in two hours and 18 minutes before Norrie restored parity against Fritz in just two minutes fewer.
After breaking in the third game of the opening set, Norrie was rarely troubled on serve - securing three successive love holds before Fritz fought back to force a deciding third set.
The American gained the upper hand and established a 3-1 lead, but the ever-resilient Norrie won five of the next six games to level the series for GB before Dart's showdown with Pegula.
Unfortunately for the Brit, the world number three proved too strong, as Pegula took under an hour to ease to a routine victory, never looking back after breaking in the opening game.
Dart won just one point on the Pegula serve in the second set bagel to put the USA 2-1 up, giving Tiafoe the chance to send his nation into the semi-finals against Evans, and he did so in two hours and 11 minutes after recovering from a set and a break down.
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Despite posting just a 54% first-serve success rate in the first set, Evans broke in the sixth game to clinch the opener before breaking immediately in the second, but Tiafoe responded straight away to get the contest back on serve.
Evans crucially squandered three break points in the 11th game before being broken again by Tiafoe, who gave the Brit a taste of his own medicine in the third set by breaking for a 4-2 lead.
Three double faults for Evans and five aces for Tiafoe turned the tide in the American's favour, as he propelled the USA into an unassailable 3-1 lead before Pegula and Fritz saw off Dart and Evans in just over an hour.
After being broken in the opening game, Dart and Evans eventually responded in the eighth game to level at 4-4, but the respite did not last long as Pegula and Fritz broke again in the ninth before holding to seal the first set.
The second set remained on serve until the ninth game, where the USA clinched the vital break before a gorgeous Fritz cross-court backhand sealed a love hold and their fourth win of the day.
Ben Knapton
