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Basel, Switzerland (SportsNetwork.com) - Swiss icon and five-time champion Roger Federer moved into the quarterfinals, while reigning champion Juan Martin del Potro posted an opening-round victory Wednesday at the $1.955 million Swiss Indoors tennis event.

The top-seeded former U.S. Open champion del Potro handled Swiss wild card Henri Laaksonen 6-4, 6-4 at St. Jakobshalle, where the Argentine upset Federer in last year's Basel finale.

The formidable Argentine del Potro's second-round opponent on Thursday will be former Australian Open runner-up Marcos Baghdatis, who was a Basel runner-up back in 2005.

The third-seeded former world No. 1 Federer came from behind to win his second-round match against Uzbekistan's Denis Istomin, 4-6, 6-3, 6-2, in 1 hour, 52 minutes on Day 3.

Federer is a nine-time Basel finalist, including the five titles. The current world No. 8 is battling for a spot in the eight-player season-ending ATP World Tour Finals in London next month.

Meanwhile, Michael Llodra ousted fifth-seeded fellow Frenchman Richard Gasquet 6-4, 6-2 in an opening-round affair, and a second-round upset came when Croat Ivan Dodig humbled sixth-seeded 2011 Basel runner-up Kei Nishikori 6-1, 6-2. The U.S. Open semifinalist and world No. 9 Gasquet is still battling for a spot in the ATP World Tour Finals. He was fresh off his title in Moscow last week.

Hot Bulgarian Grigor Dimitrov is seeking his second title in two weeks, as the eighth seed reached the second round with a 6-3, 6-3 spanking of Czech veteran Radek Stepanek. Dimitrov will meet Ukrainian Alexandr Dolgopolov in the round of 16.

The 22-year-old Dimitrov secured his first-ever ATP title in Stockholm last week.

In some other first-round play, Canadian Vasek Pospisil vaulted past last week's Vienna runner-up Robin Haase 6-4, 6-4 and Frenchman Paul-Henri Mathieu got past American fellow qualifier Denis Kudla 6-4, 7-5.

The 2013 Basel winner will earn $475,000.