Federer progressed to the third round of the Indian Wells by beating Federico Delbonis in straight sets but the match was delayed midway through because of rain.
The Swiss star took the first set 6-3 in the night session before the weather forced the game to be reschedule with the score at 2-2 in the second.
The following morning the two players returned to court and neither could get a real breakthrough as they held serve to take the match to a tie-break.
Federer showed his experience to snatch an 8-6 win and take the match 6-3 7-6.
However, the 36-year-old explained how difficult it is to return and face the same opponent in different conditions.
“When you go from night to day [in consecutive days, you’re usually] playing a different opponent,” said Federer.
“So naturally, it’s all a change.
“Whereas, here now you play the same guy the next day, so you can really compare, you know, how different conditions are.
“It was actually quite interesting.
“The nighttime is much deader.
“The surface doesn’t react so much; the ball doesn’t travel so fast… So talking about faster, I just think there is more bounce to it, especially if you play someone who has a lot of spin like he has and kicks the ball around a lot.”
Federer will be hoping to continue his 100 per cent start to the 2018 season when he faces Filip Krajinovic in the third round.