The young German pushed the 19-time Grand Slam champion hard, but ultimately it was the Swiss who triumphed – securing his path to the semi-finals in the process.
Zverev received some kind words from the 36-year-old in the aftermath of the match, with Federer labelling him as the ‘complete package’.
But while the 20-year-old was frustrated to not claw his way back into the match, he showered the eight-time Wimbledon winner with praise for how he always can ‘disturb’ his opponents.
‘I mean, look, I’ve played Roger now six times,’ he said after the 6-7 (6-8) 7-5 1-6 defeat at the O2.
‘We’re 3-all now, if you count the Hopman Cup match. As I said, it was a great match.
‘He’s the best player of all time. He’s always going to find a way to try to disturb your rhythm a little bit to try and win.’
Zverev had beaten Federer in the final of the Montreal Masters to become one of just four men to inflict a loss on the Australian Open champion in what’s been a remarkable season.
But he made 45 unforced errors in London, particularly struggling with low, short balls off his forehand side.
And Zverev believes players are starting to understand his game better, which is why Federer used plenty of slice to the backhand to cause him problems.
‘As I said in the last match already, I think people have realised that if you go fast to my backhand with a lot of spin, I quite like it,’ he added.
‘So maybe people are starting to change it up, go a little more with the slice.’