Nick Kyrgios smashed a racquet and tossed it in the stands on his way to defeat in the Murray River Open Friday as he struggled with injury ahead of the Australian Open on Friday.
The Australian showman was hampered by left knee pain during his 6-3, 6-4 loss to Croatia's Borna Coric and appeared on the verge of pulling out after the first set.
"I can't serve without pain... when I land it feels unstable," he told a trainer after the first set.
He opted to continue but was given a warning for swearing, then demolished his racquet and threw it into the empty stands when broken on serve.
"I'm not sad. I'm not disappointed at all," he said afterwards, describing his knee as "pretty sore".
"I played three matches this week, which is exactly what I needed. Now I got a couple days, three or four or five days, to just relax a little bit, fine-tune a couple things, then see how it goes in the Oz Open."
On a day when players backed up for a second match, after Thursday's schedule was suspended over a coronavirus case, Coric returned later for a quarter-final clash with Britain's Dan Evans but crashed 7-5, 7-6 (7/1).
Evans will face Jeremy Chardy in the semi-finals. The Frenchman eased past American Taylor Fritz 6-2, 6-4 then received a walkover when three-time Grand Slam winner Stan Wawrinka opted out of their last-eight clash.
Meanwhile Italian teenager Jannik Sinner, who in November became the youngest ATP champion in 12 years when he won in Sofia, powered into the last four of the Great Ocean Road Open.
Having beaten Slovenia's Aljaz Bedene 7-6 (7/6), 6-2 earlier in the day, he returned to sweep past Serbia's Miomir Kecmanovic.
Sinner will face second seed Karen Khachanov in the semis after the Russian beat former world number five Kevin Anderson then Dutchman Botic Van de Zandschulp to secure his spot.
Brazilian Thiago Monteiro takes on Italy's Stefano Travaglia in the other Great Ocean Road semi.