Federer Edges Into Simon Australian Open Thriller
Federer had to pull out all the stops to ignore the unseeded Simon won 6-2, 6-3, 4-6, 4-6, 6-3 3h 13min and the Rod Laver Arena.
Swiss world number two crossed a two-set lead, but Simon, who won his only other two meetings, responded dramatically to take the contest into a deciding fifth set.
Federer was relieved to come away with a win in five sets and avoid losing for the first time in the second round in a Grand Slam tournament since the French Open in 2003.
"Today I was lucky enough to go through," Federer said.
"It's a great player. Matches against him do not come easy and always go the distance. Hopefully I will not play as much," she laughs.
Federer will face Xavier Malisse of Belgium in the third round on Friday.
Roger Federer's victory tied the Swede Stefan Edberg record (56-10) for most victories in the Open Era at the Australian Open. Federer now has a 56-7 win-loss record at Melbourne Park.
All-time Grand Slam champion with 16 major titles, is bidding to become the second man to win five Australian titles, behind six-time winner Roy Emerson.