The incredible moment left Kyrgios and tennis commentators in shock.
Regrettably, the other most notable talking points all surrounded Kyrgios' unreliable mental state and energy level.
As he drifted in and out of the match, Federer stayed on target and never truly looked like being beaten, despite both the first and third sets going deep on serve before the former World No. 1 was able to pounce with a break of serve.
American tennis legend John McEnroe again led the public criticism of Kyrgios' performance — saying he simply hopes the Australian is able to learn from the lesson Federer handed out.
"I like Nick as a person, (but) you don't want his behaviour rewarded," McEnroe told ESPN.
"Some of his behaviour that is questioned. You need to be more dedicated if you want to be there with the big boys. So in a way it's a good message and hopefully one he (Kyrgios) can learn from."
Kyrgios dropped seven straight games during a stretch from 4-4 in the first set to 5-0 in the second set.
It prompted a trademark Kyrgios dummy spit where he was seen swearing in the direction of his players box.
He was never able to recover from it.
Kyrgios raged towards his players' box when sitting down at the end of the first set, appearing to lose his cool when looking for support from his courtside team.
"Why is it always about the serve? Say something else," Kyrgios said towards his box.
"'Move my feet' or something. Why is it about the serve every time? F***ing 'first serve, first serve, first serve'. Obviously I'm trying to make my f***ing first serve."
It was trademark Kyrgios. As always there were enough flashes of brilliance to make you think anything was possible.
Federer showed very quickly why an upset was never really a possibility on this day in New York.
The 20-times grand slam champion produced some at-times breathtaking shot-making in sweeping past Kyrgios 6-4 6-1 7-5 in their much hyped third-round showdown at Arthur Ashe Stadium.
Federer's emphatic victory set up a last-16 meeting with another Australian, unseeded journeyman John Millman, on Monday.
Saturday's blockbuster was billed as the match of the first week. In a bold statement of intent, Kyrgios stole a move right out of the Federer playbook with an audacious SABR (sneak attack by Roger) on his opening return of the match.
The daring ploy didn't pay immediate dividends, but it wasn't long before Federer was looking unsettled as Kyrgios continued to apply niggly and offbeat tactics.
Not for the first time, but certainly for the first time while actually playing Federer, Kyrgios even mimicked the great Swiss's service motion in the fourth game.
He had the great Swiss down love-40 in the seventh game, Federer needing to stave off four break points to keep the Australian at bay after a ferocious early fight.
Federer's tenacity reaped rewards with the second seed stealing the opening set with a backhand return pass on a rare Kyrgios serving lapse.
The setback marked the beginning of the end for Kyrgios, who gave his courtside box a sarcastic thumbs up after dropping serve again, from 30-love up, to fall behind 3-0 in the second set.
Kyrgios started as the entertainer but it was now Federer putting on the show, the 20-times major winner flicking a sublime backhand winner then rifling a forehand cross court to charge to 5-0 before seizing a two-sets-to-love lead with his 10th ace.
He'd lost just three times in an incomparable 1424-match career from such a commanding position and wasn't about to suffer a fourth such defeat at the hands of Kyrgios.
Five of the pair's previous six sets contested had gone to tiebreakers, but it was clear Federer was up for this one.
Even Kyrgios could only marvel "oh my god" in disbelief as 37-year-old Federer pulled off a lunging forehand on the run around the net post as he closed in on victory in the third set.
The match was as good as over when the five-times champion broke Kyrgios for a fourth time for 6-5, before closing out victory after one hour and 44 minutes.
