Roger Federer beat Adrian Mannarino 6-4 6-2 in the first round of his hometown Swiss Indoors event in Basel.
Race to London
(ruled out through injury)
Juan Martin Del Potro
Standings correct as of Monday, 21 October
Federer, 32, won the final five games in succession against the 25-year-old Frenchman to progress in 71 minutes.
The five-time champion needs to perform well in Basel and the upcoming Paris Masters to retain hopes of qualifying for the eight-man ATP World Tour Finals tournament next month.
"I'm concentrating on playing well and hoping to qualify for London," he said.
The top eight-ranked players in the ATP rankings qualify for the World Tours Finals at the O2 Arena, which runs from 4-11 November.
Britain's Andy Murray has already
withdrawn from the season-ending event in London
as he continues his recovery from back surgery, meaning ninth place with qualify.
Seventeen-time Grand Slam winner Federer will face either Uzbekistan's Denis Istomin or Argentina's Horacio Zeballos in the second round in Basel.
Federer has qualified for the season-ending tournament every year since 2002, winning it six times.