Wildcard Rinky Hijikata and journeyman Jordan Thompson have prevailed in two all-Australian affairs on a banner day for the home hopes at the Brisbane International.
Hijikata, Thompson, qualifier James Duckworth and Rafael Nadal-hunter Jason Kubler joined Alexei Popyrin in the last 16 on Tuesday.
Flying at a career-high ranking after making the US Open fourth round in September, Hijikata struck another blow for the new generation with a 7-6 (10-8) 6-2 win over Thanasi Kokkinakis.
The 22-year-old next faces Czech qualifier Tomas Machac for a quarter-final berth.
Thompson outclassed Aleksandar Vukic 6-3 6-2 to book a second-round date with either French fourth seed Ugo Humbert or American qualifier Alex Michelsen, who play on Friday.
Duckworth earlier overcame a frustrating rain delay to continue his fine run from qualifying to reach the second round of the weather-marred Australian Open lead-up event.
Duckworth upset higher-ranked American JJ Wolf 6-3 6-4 in a match initially scheduled for Monday morning but which didn't start until Tuesday afternoon.
The wild storms that hit south-east Queensland over the Christmas period have caused chaos for tournament organisers who face a backlog of matches to get through this week.
Duckworth did his best to help, taking just 63 minutes to see off the 53rd-ranked Wolf with a clean and efficient display featuring no service breaks, seven aces and 81 per cent of first-serve points won.
The world No.116's reward is an enticing opportunity to reach the quarter-finals after unfancied German Yannick Hanfmann ousted Duckworth's slated last-16 opponent, American fifth seed Sebastian Korda, 7-5 6-4.
Kubler earned an even bigger prize after Russia's 2021 Australian Open semi-finalist Aslan Karatsev, the tournament's eighth seed, retired two sets into their deadlocked first-round contest.
Karatsev had just taken the second set in a tiebreaker before quitting with injury, leaving Kubler to take on returning 22-times grand slam champion Rafael Nadal on Thursday for a quarter-final spot.
In his first outing in almost a year, Nadal dazzled fans with a 7-5 6-1 victory over four-times major finalist and 2020 US Open champion Dominic Thiem.
