The top-three seeds in the men's Sydney International tennis draw were sent crashing on Wednesday.
Former world number 4 Juan Martin Del Potro, who was handed a wildcard after his ranking tumbled to 338 following an 11-month injury lay-off, beat top-seeded Italian Fabio Fognini in 3 sets.
Second seed David Goffin of Belgium was sent packing by Italian Simone Bolelli with Australian Bernard Tomic accounting for the German third seed Philipp Kohlschreiber in straight sets.
It leaves last year's finalists Tomic and Del Potro on course for a rematch on Sunday.
Former US Open champion Del Potro needed treatment from the courtside trainer during the first set but said there was no major discomfort from his left wrist.
He also said he had no issues with umpire Fergus Murphy who took exception to his slow return to the court from a change of ends and issued a code violation against him.
Poland's Jerzy Janowicz, who beat Australia's Nick Kyrgios in the first round, crashed out to fifth-seeded Argentine Leonardo Mayer.
Number four Julien Benneteau is the highest seeded player left in the draw after beating Canada's Vasek Pospisil.