Crowd favourite Thanasi Kokkinakis has failed to reproduce his Australian Open first-round heroics, outclassed by in-form Bulgarian Grigor Dimitrov.
A packed house at John Cain Arena on Thursday night couldn't lift Kokkinakis to an upset win over the world No.13, who triumphed 6-3 6-2 4-6 6-4.
The loss leaves Alex de Minaur as the only remaining Australian male in the tournament.
After a gruelling five-set thriller against Austrian Sebastian Ofner in the opening round, Kokkinakis said he was troubled by a hip issue that meant his serve wasn't at full power.
But he could't blame the injury for the loss.
"It was tough. He is playing incredible tennis at the moment," Kokkinakis said.
"I felt like I couldn't get the ball past him, he's moving unbelievably well.
"I just felt like I had to work for everything and got very few free points. He is definitely in some great form right now."
Dimitrov broke the South Australian early in the first two sets to set up the victory and played some flawless tennis that didn't allow the world No.80 many chances to find his way back into the match.
The gutsy Kokkinakis stayed with Dimitrov in the third set. Up 5-4, he had two break points on Dimitrov's serve and clinched the set when his rival netted a backhand.
The 27-year-old went toe to toe in the fourth set until losing his serve to trail 4-5, allowing the veteran to serve out the match to love.
"I got a bit passive at some point and got away from my game ... but I kept on being composed and stayed within myself," Dimitrov said.
"I couldn't get too hung up on the mistakes that I was doing. He was playing good tennis and he was pressing me and I had too many opportunities, but I couldn't convert.
"I just had to be patient and I served it out beautifully."
Their unforced error count was almost the same, but former world No.3 Dimitrov, who won the Brisbane International lead-in tournament, came up with the big plays when it mattered most.
Dimitrov, whose best result at Melbourne Park was a semi-final showing in 2017, finished with 68 winners to 40 from Kokkinakis, while he was particularly dangerous at the net.
He will next face Portugal's Nuno Borges, who saw off Spanish 23rd seed Alejandro Davidovich Fokina.
