Roger Federer made a confident start in his bid to claim an eighth Cincinnati Masters title, the Swiss brushing aside Peter Gojowczyk in straight sets on Tuesday.
A winner at the ATP Masters 1000 event in Ohio as recently as 2015, Federer was playing for the first time since turning 37 last week.
But the second seed made light of his status as the sport's elder statesman by easing to a 6-4 6-4 victory in one hour and 13 minutes against the German world number 47.
The highest ranked player in the field in Rafael Nadal's absence, Federer will now face Argentina's Leonardo Mayer for a place in the quarter-finals.
Gojowczyk initially held his own up against the Swiss great, but when a backhand down the line on the run went long in the fifth game, the crucial first break went Federer's way.
Some signs of rust were present from a player who had not competed since his surprise defeat to Kevin Anderson at Wimbledon, Federer offering up three break points in a lengthy eighth game.
But Gojowczyk proved unable to take them, Federer later coming to the net and putting away a confident backhand volley to hold to love and take the opener.
The scale of the challenge facing Gojowczyk grew when he sent an awkward backhand wide to give up a break in the first game of the second set.
Having consolidated that break, Federer's genius was soon on display as he served and then conjured up a perfectly judged drop shot volley to move 4-2 ahead.
And while Gojowczyk held his serve throughout the remainder of the second set, Federer did not put a foot wrong, holding to love to win it on his first match point.
