Great Britain’s hopes of reaching the semi-finals of the United Cup depend on Katie Boulter beating five-time major champion Iga Svitek after Billy Harris was beaten by former Wimbledon semi-finalist Hubert Herkaz.
Harris, 29, pushed 16th-ranked Harkaz in the opening match of a best-of-three tie before losing 7-6 (7-3) 7-5 in Sydney.
Late opener Harris, who is ranked 125th in the world after a huge rise over the past two years, wanted to provide the platform for Great Britain to reach the last four with the biggest win of his career.
His defeat means the 28-year-old bolter will have to beat Switek later on Thursday to win the deciding mixed doubles match.
Harris is playing as Britain’s leading man in the mixed-gender team event with Jack Draper out with a hip injury and Cameron Norrie playing the ATP event in Hong Kong.
While he served strongly, Harris failed to break through and fell short in crucial moments.
Neither player faced a break point in a tight first set until the Brit fought back two chances for Harkaz in the 12th game, eventually hanging on to his serve to force a tiebreak.
A costly error from Harris – a long foul with an overhead – handed Herkaz an early mini-break, which he showed at the highest level with a clinical lead.
Despite falling behind, Harris showed her mental toughness in the second set. He quickly reset to make three break points in the second game, only for Harkaz to fight back from 0-40 down with five great serves to make it tough.
Harris eventually broke when Harkaz took a 6-5 lead and, with the wind out of Britain’s sails, the 27-year-old Pole held to love to seal a quick victory.
“I’m very happy, it was a tough battle with Billy,” said Harkaz, whose run to the semifinals at Wimbledon in 2021 is his best performance at a major.