Australian wildcard Jordan Thompson set up a date with top seed Bernard Tomic in the second round of the Apia International in Sydney.
The world number 149 earned his first ATP tour main draw victory when Martin Klizan retired while 6-2 4-0 down in their first round encounter.
Tomic - ranked 132 places above his compatriot - received a bye into the second round and will be looking to improve on reaching the quarter-finals last year.
Fifth seed Andreas Seppi produced a strong display in the third set to overcome Denis Istomin in the first round.
The Italian claimed the first set but saw the Uzbek fight back from a break down to force a decider. Seppi never looked like slipping up, though, as he saw out a 6-4 4-6 6-2 triumph.
Simone Bolelli struggled up against Alex Sarkissian, losing 6-2 7-6 (7-5) to the world number 195.
In the day's remaining matches, Pablo Cuevas progressed beyond Maximilian Marterer 6-4 6-4, while Tommy Robredo beat John Millman in straight sets 7-6 (7-3) 6-3.