Sydney, Australia (SportsNetwork.com) - Juan Martin del Potro came back from a set down to defeat top seed Fabio Fognini in second-round action Wednesday at the Sydney International tennis event, a final Australian Open tune-up.

The reigning champion from Argentina beat Fognini by a 4-6, 6-2, 6-2 margin on the hardcourts at NSW Tennis Centre.

The oft-injured 2009 U.S. Open champion del Potro has won his first two matches since being sidelined for 11 months with a wrist injury.

The tall slugger, unseeded this week, beat Aussie and 2013 Sydney titlist Bernard Tomic in last year's final here. Del Potro will meet Kazakhstani qualifier Mikhail Kukushkin, who upset Uruguayan sixth seed Pablo Cuevas 7-5, 7-5, in the quarterfinals.

Second-seeded David Goffin of Belgium also lost, falling to Simone Bolelli of Italy 6-3, 6-3, while the Aussie Tomic defeated third-seeded Philipp Kohlschreiber of Germany 6-3, 6-4.

Next up for Bolelli is 2011 runner-up Viktor Troicki, who outlasted Spaniard Pablo Andujar 4-6, 6-3, 6-3. Tomic will next meet Luxembourg's Gilles Muller, who took down No. 7 Frenchman Jeremy Chardy 2-6, 7-6 (7-1), 6-4.

Also, fourth seed Julien Benneteau of France defeated Canadian Vasek Pospisil 7-6 (7-3), 6-3 and No. 5 seed Leonardo Mayer beat Poland's Jerzy Janowicz 4-6, 6-1, 7-6 (7-3).

This week's winner will claim $80,000.