The 2009 champion struck 48 winners and won 19 of 24 points at net in the 93-minute match, improving to 8-0 lifetime against the 204th-ranked Istomin.
Ruthless Federer into second round after impressive opening win
Federer asserted himself right away, breaking to 15 in the opening game of the match, aided by a pair of double faults by Istomin. He attained a second break with a forehand winner to go in front 5-2.
Serving for the set, the Swiss fell into a 15-30 hole, but struck back-to-back aces to bring up set point and he hit a deep serve that Istomin was unable to do anything with and Federer was on his way.
Istomin saved a pair of break points in the opening game of the second set to hold, but a forehand error in his next service game gave Federer the advantage at 2-1. The Uzbek did well to hang in the set, but an ace on set point gave Federer a two-set lead.
The third set went to serve through the first four games, but in the fifth, a backhand volley gave Federer triple break point and after failing to convert on the first two, a forehand winner on the third put him on top 3-2.
Istomin did well to save a break point and hold to cut the deficit to 4-3, but serving to stay in the match, he meekly dumped a forehand slice into the net as Federer advanced in clinical fashion.