Seventh seed Jan-Lennard Struff moved safely through to the last 16 of the Adelaide International, while Dan Evans reached the quarter-finals.
Struff was the only seed in action on Tuesday at the first edition of the tournament and he defeated lucky loser Salvatore Caruso 6-4 6-2.
Like Struff, Spaniard Albert Ramos-Vinolas won his first-round match, as did qualifier Tommy Paul and wildcard Alex Bolt.
Evans, meanwhile, is the first man into the last eight after he saw off Alexander Bublik 7-5 6-2.
Inclement weather heavily affected proceedings at the Auckland Open, though there was still time for John Millman to reach the last 16 with a hard-fought 7-6 (7-5) 6-4 win over qualifier Michael Mmoh.
Millman will play Karen Khachanov in round two, with Vasek Pospisil – a winner over Joao Sousa – set to face rising star Denis Shapovalov in an all-Canadian encounter.
Kyle Edmund defeated wildcard Alejandro Davidovich Fokina 6-2 4-6 6-3 in a back-and-forth contest.
A great match despite the rain interruptions
— ATP Tour (@atptour) January 14, 2020