Hijikata belied his world ranking of No.62 to beat the 10th seed, Russian-born Kazakhstani player Alexander Bublik, 6-7 (3-7) 7-6 (7-3) 6-3 at Indian Wells on Monday (Tuesday AEDT) to book his spot in the round of 16.
His next opponent is left-handed Englishman Cameron Norrie, who had earlier upset another Aussie, sixth-seeded Alex de Minaur, in straight sets.
Hijikata showed nerves of steel to bounce back after losing the first set, claiming the second in another tiebreak, before making the only service break of the match in the decider.
Bublik crunched more winners than Hijikata (40-33), but also made a lot more unforced errors (49-27).
The Aussie was rock-solid on serve, not giving up any break points, while managing to convert one of the seven opportunities he set up against Bublik.
It was Hijikata's first win over a top-10 player.
Twelve months ago Hijikata lost to Bublik at the Phoenix Challenger, after a second round exit at Indian Wells.
"It was a bloody tough second round of a Challenger last year, and I'm glad we could play in the second week here this year," he said.
"Obviously, he's a quality player. He's had a hell of a year, never easy to face, so I'm just pumped to get through.''
Earlier, de Minaur's run came to a screeching halt against Norrie.
The world No.6 failed to flourish in the Southern California desert, his British opponent bringing the heat in a 6-4 6-4 win.
De Minaur had been hoping to improve on last year's round-of-16 result, but couldn't make it past the third round this time at the ATP 1000 event, which many consider the sport's fifth grand slam.
The Aussie blasted 25 winners compared with Norrie's 16, but also coughed up more unforced errors - 30 to the Brit's 22.
Left-hander Norrie, ranked No.26 in the world, also came up trumps with his service, winning 76 per cent of points off his first delivery, compared with de Minaur's 66 per cent.
And de Minaur, considered one of the finest returners in the game, finished second-best when it came to breaking serve. Norrie converted three of the four break points he set up, while de Minaur only cashed in one of the seven opportunities he created.
Norrie, the 2021 Indian Wells champion, was joined in the fourth round by fellow Brit Jack Draper, a 6-1 7-5 winner over Argentina's Francisco Cerundolo.
Draper's victory set up a match against third seed Novak Djokovic, who overcame a second-set hiccup to beat American Aleksandar Kovacevic 6-4 1-6 6-4 and reach the last 16 for the first time since 2017.
The 24-time grand slam champion, who has won a record-equalling five titles at the California desert event, won the first set but was taken apart in the second, before asserting his authority to seal victory in two hours and two minutes.
- with Reuters
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