Alex de Minaur’s hopes of maintaining his fine start to the US hard-court circuit have been crushed, knocked out of the ATP event in Washington by a player ranked 73 places lower than him.
De Minaur served for a spot in the last 16 in the second set, then had match point in the tiebreak, but let both opportunities slip against world No.94 Yoshihito Nishioka.
The Japanese won 3-6 7-6 (8-6) 6-2 in a contest lasting two hours 35 minutes.
Alexei Popyrin was the second Aussie eliminated on Wednesday in the US capital, going down 6-4 6-3 to the third-seeded American Taylor Fritz inside 72 minutes.
Australia’s No.1 male de Minaur had begun the US swing in good form, winning the title in Atlanta last week.
In the early exchanges against of his Citi Open round-of-32 match against Nishioka, it looked as De Minaur, the 11th seed, would continue that bright start.
He won the opening set in 37 minutes, breaking in the sixth game, then overcoming a slight wobble when serving for the set at 5-3.
Broken in his second service game in the second stanza, de Minaur broke back twice to lead 5-3. He again served for the set – and the match – this time at 5-4, but slipped to 0-30 and could not recover.
It went to a tiebreaker, in which de Minaur grabbed an early mini-break to be 3-1 up. He then lost three successive points, battled back to force a match point, but failed to take it and was beaten 8-6.
De Minaur was broken in the opening game of the final set and soon found himself 0-3 down. He broke back once but it was not enough.
Nishioka now meets Russian Karen Khachanov in the next round.
Elsewhere, second seed Hubert Hurkacz of Poland was beaten 6-4 7-6 (7-3) by Finn Emil Ruusuvuori.
Sixth-seeded Canadian Denis Shapovalov suffered a 2-6 7-6 (7-5) 3-6 defeat at the hands of J.J. Wolf while No.12 seed Sebastian Baez of Argentina lost 6-1 6-4 to Sebastian Korda
Bulgarian fifth seed Grigor Dimitrov was a 6-1 3-6 7-5 winner over Adrian Mannarino of France and Danish ninth seed Holger Rune progressed past veteran Frenchman Benoit Paire 6-3 6-2.
Nick Kyrgios stemmed the flow of Aussie exits with a 6-3 6-4 win over Tommy Paul in the late match.
Kyrgios faces Reilly Opelka next for a quarter-final spot after the American defeated countryman Denis Kudla 6-7 (8-6) 6-4 6-4.