That is the view of Greg Rusedski, who saw Federer book his place in the fourth round of the US Open after a crushing win over Kyrgios.
Federer took apart Kyrgios in straight sets – 6-4, 6-1, 7-5 – to keep himself on track to lift the title at the Flushing Meadows for the first time since 2008.
The Swiss legend produced an ingenious bit of skill in the third set when he picked up a Kyrgios drop shot, flicked out a forehand around the net post and down the line.
And it was a shot that left Rusedski in awe.
Speaking on Amazon Prime’s live coverage after the match, he said: “After the first set, Federer was the man and he went from strength to strength.
“He dominated the second set and the third set was like a highlights reel.
“There was only ever going to be one winner after the first set.
“Let’s look at one of the greatest shots that we’ve possibly ever seen.
“It is sensational and I can’t believe Kyrgios got there.
“For Federer at 37 to get it past the post and squeak it up the line.
“Look at the reaction Kyrgios, ‘it’s like mate you can’t be serious!’.
“It was just sensational.”
Federer will now face Kyrgios’ countryman John Millman in the round of 16.