Emma Raducanu is out of the Auckland Classic after falling to a 6-7 (5-7) 7-6 (7-3) 6-1 defeat by second seed Elina Svitolina in the second round.
The Briton, playing her second match since wrist and ankle surgeries, raced into a 5-1 lead in the first set before taking it in the tie-break.
Svitolina won the second after another tie-break and, with Raducanu tiring, took the third in just 31 minutes.
Next up for Raducanu is the Australian Open, which begins on 14 January.
The 2021 US Open champion was playing with fairly heavy strapping on her right thigh but went toe to toe with world number 25 Svitolina before fading after an intense first two sets that each lasted more than an hour.
While Raducanu’s focus turns to the first Grand Slam of the year in Melbourne, Svitolina progresses to the Auckland quarter-final where she will play Czech Republic’s Marie Bouzkova.
Encouraging signs in defeat for Raducanu
After a hard-fought victory over Romania’s Elena-Gabriela Ruse in the first round, this was another gruelling encounter for Raducanu as she continues her return from injury.
The 21-year-old began well to go a double break up but was twice unable to convert when serving for the first set.
However, she showed her resilience in the breaker, setting up her first set point with a drop shot and – after a double fault – converting the second with a deft forehand.
Svitolina came fighting back at the start of the second with Raducanu saving two break points in the opening game, only for Ukraine’s former world number three to convert the third.
Raducanu broke back immediately, but Svitolina made it three games against the serve in a row to restore her advantage.
Again, Raducanu hit back though with another break to make it 3-3 and from there it stayed on serve to set up another tie-break.
The Briton went up 3-1 before Svitolina reeled off six straight points to level the contest and never looked back.
Raducanu was showing signs of fatigue with two unforced errors gifting Svitolina a pair of break points in the first game of the third set. They were repelled, with a third saved with an ace, but a double fault eventually gave Svitolina the break.
There was no way back for Raducanu, who looked understandably weary after a long injury absence from the tour, and an energised Svitolina ruthlessly finished the job.
Analysis: Fatigue no surprise
Russell Fuller, BBC tennis correspondent
The fatigue in the final stages was no surprise – the match was already into its third hour when the deciding set began, and that’s not a comfortable place for someone playing just their second match in eight months.
But Raducanu’s performance in the first two sets was extremely good. By nature an aggressive player, she was also very impressive in defence and there was selective but effective use of the drop shot.
Her next competitive appearance will be in the main draw of the Australian Open, but it is quite possible she will first play an exhibition match or two at next week’s Kooyong Classic in Melbourne.
Dart reaches last four in Canberra
Elsewhere, Harriet Dart beat second seed and world number 93 Nao Hibino 6-3 6-0 to reach the Canberra International semi-finals.
It is the first time in Dart’s career that she has won a set 6-0 against a top 100 opponent on a surface other than grass.
World number 120 Dart will face American Katie Volynets for a place in the final.
Top seed Coco Gauff breezed through to the last eight in Auckland after a straight-set win over Brenda Fruhvirtova of the Czech Republic. The American won 6-3 6-0 and will play France’s Varvara Gracheva in the quarter-finals.
At the Brisbane International, Kazakhstan’s Elena Rybakina cruised into the quarter-finals with a 6-1 6-0 win over Elise Mertens of Belgium, while 16-year-old Russian Mirra Andreeva also advanced with a 6-1 6-1 triumph against Australia’s Arina Rodionova.
Victoria Azarenka will face Jelena Ostapenko in the last eight after each won their last-16 matches. Azarenka overcame France’s Clara Burel 7-5 6-2 while Ostapenko beat Czech Republic’s Karolina Pliskova – who knocked out Naomi Osaka in the previous round – 6-2 4-6 6-3.
Meanwhile, Oliver Crawford, who has two parents from Birmingham, has this week switched his nationality from the United States to Great Britain.
The 24-year-old from South Carolina, who has a world ranking of 215, becomes the British number nine, and earned his place in Australian Open qualifying with impressive results on the ITF and ATP Challenger Tours in the latter months of 2023.
His only previous appearance in Grand Slam qualifying came at the 2022 US Open, where he lost in the first round to Geoffrey Blancaneaux of France.
Olivia Martin is a dedicated sports journalist based in the UK. With a passion for various athletic disciplines, she covers everything from major league championships to local sports events, delivering up-to-the-minute updates and in-depth analysis.