Seventh seed Kei Nishikori was knocked out of the US Open by 20-year-old Australian Alex de Minaur in the third round.

The Japanese, runner-up here in 2014, went two sets down before a brief fightback in a 6-2 6-4 2-6 6-3 defeat.

For Australian world number 38 De Minaur, one of the game's rising stars, it was his first win over a top-10 player.

He will face Bulgarian Grigor Dimitrov or Poland's Kamil Majchrzak next.

"This is where I feel like my game's at," De Minaur said after reaching the last 16 of a Grand Slam for the first time.

"I want to be pushing second weeks of Grand Slams and putting myself out there. So very happy. Hopefully I can just keep it rolling."

Last year the Australian squandered a two-set lead against 2014 champion Marin Cilic to lose in five sets in the third round here.

"Last year it was a bit of a heartbreaking match for me," he said. "It stung a lot, but you learn so much from it. You know that that's your level."

De Minaur, who has won two ATP titles this year, is joined in the last 16 by Stan Wawrinka, who reached the fourth round for the first time since winning the title in 2016.

The Swiss 23rd seed edged a tight encounter with Italian Paolo Lorenzi 6-4 7-6 (11-9) 7-6 (7-4) to set up a meeting with defending champion Novak Djokovic or American Denis Kudla.

Meanwhile, Belgium's David Goffin beat Spaniard Pablo Carreno-Busta 7-6 (7-5) 7-6 (11-9) 7-5 and will next take on 20-time Grand Slam champion Roger Federer, who knocked out Briton Dan Evans.