The 32-year-old, who will also confirm his place at the season-ending ATP World Tour Finals if he wins the tournament, hit back from behind to triumph 4-6 6-3 6-2 in one hour and 51 minutes in the second-round clash.
Top seed Juan Martin Del Potro, who denied Federer that sixth crown in last year's final, started his defence with a surprisingly tricky 6-4 6-4 win over 21-year-old Swiss wild card Henri Laaksonen.
Fresh from his first career title in Stockholm last weekend, Bulgaria's Grigor Dimitrov started with a 6-3 6-3 win over Czech veteran Radek Stepanek.
Fifth seed Richard Gasquet was beaten 6-4 6-2 by fellow Frenchman Michael Llodra, and sixth seed Kei Nishikori also tumbled, beaten 6-1 6-2 by Ivan Dodig of Croatia.
There were also wins for Frenchman Paul-Henri Mathieu, 6-4 7-5 over fellow qualifier Denis Kudla, and Canadian Vasek Pospisil, who beat Dutchman Robin Haase 6-4 6-4.