Duckworth into Brisbane quarter-finals, world's top 100

The 31-year-old's plucky victory reversed a three-set loss to the German at the Shangha Masters in October and guaranteed at least one home hope in the last eight of the Australian Open lead-up event.

Fellow Australian Alexei Popyrin is also in action on Wednesday, while Rinky Hijikata, Jordan Thompson and Jason Kubler - up against the great Rafael Nadal - all return for second-round matches on Thursday.

Duckworth will play either Danish top seed Holger Rune or Russian Alexander Shevchenko for a place in the semi-finals.

Either way, the 31-year-old is guaranteed to rise at least 20 spots in the rankings next Monday from world No.116 to provisionally 96th.Duckworth upset higher-ranked American JJ Wolf 6-3 6-4 in a first-round match initially scheduled for Monday morning but which didn't start until Tuesday afternoon.