New York - Alex de Minaur said "this is where I want to be" after dumping out Kei Nishikori at the US Open on Friday to reach the last 16 at a Grand Slam for the first time.
The 20-year-old Australian defeated 2014 runner-up Kei Nishikori in four sets to earn a first win over a top-10 player at the 12th attempt and advance to a meeting with Grigor Dimitrov or Polish lucky loser Kamil Majchrzak.
De Minaur also moved on from the anguish of last year's five-set loss against Marin Cilic in the third round, and is on a potential quarter-final collision course with five-time champion Roger Federer.
"I had a little bit of a thriller last year versus Cilic and was two sets to love up. I was glad I could finally get the win," De Minaur said, stamping out the threat of a Nishikori comeback in a 6-2, 6-4, 2-6, 6-3 win.
"Last year it was a bit of a heartbreaking match for me. It stung a lot, but you learn so much from it. You know that that's your level."
"I have been in this situation before, and this is where I want to be," he added. "This is where I feel like my game's at.
"I want to be pushing these guys, I want to be pushing second weeks of Grand Slams and putting myself out there."
De Minaur, currently ranked 38th, started the year by lifting his maiden ATP title in his native Sydney and reached the Australian Open's last 32 before falling to eventual finalist Rafael Nadal.
But a nagging groin injury, which forced him to take anti-inflammatory medication, stalled his progress and De Minaur, reliant on his quicksilver court speed, went winless for three months.
He marked his return to form last month with a second career trophy in Atlanta, a run that was accompanied by a pencil-like moustache -- charmed facial fluff that yielded success but was soon discarded.
"It takes me like 17 years to grow that moustache. Maybe in a couple years' time but not any time soon," De Minaur said, asked whether the moustache could make a reappearance.
Nishikori had reached the quarter-finals at all three previous Grand Slams this year, but his defeat by De Minaur consigned the Japanese star to his earliest exit since Wimbledon in 2017.
"I made it tougher for myself to get each game. It was too many unforced errors. I wasn't as consistent as I'm used to," Nishikori said.
"Both things considered I think he played good and for me in certain moments I didn't play well."
Nishikori failed to win a match in US Open tune-up events in Montreal and Cincinnati, but he said that had little bearing on his struggles at Flushing Meadows.
"It was OK before coming into this tournament. I was having good practice and confidence. But today he just played good."