Federer showing his class, did not waste much time in clinching the second set and easily cruised to the winning mark, thrashing Zverev 6-3 in the second set.
Playing in his 140th career final, the remarkable 35-year-old, who has won the All England Club title seven times but not since 2012, became the oldest victor of the Wimbledon warm-up tournament despite taking the entire clay-court season off.
The 20-year-old Zverev also had been 3-0 in title matches this season before Sunday, winning in Montpellier, Munich and Rome, where he beat world No. 2 Novak Djokovic for his first ATP World Tour Masters 1000 title.
McEnroe: Williams would be ranked 'like 700' on men's tour
Tennis champion Serena Williams may be expecting her first child, but she is already planning her return to the court. McEnroe elaborated that the thought Serena's incredible mental strength would allow her to beat some male players.
Federer - who lost to Tommy Haas at the Stuttgart Open last week as he returned to action following a two-month break - coasted through the opening set.
The 28-ranked Khachanov fired a backhand long in the breaker to send Federer through to a showdown with Zverev.
"You could have been a bit nicer and allowed me a couple more points", Zverev joked to his idol.
Rivals Hamilton, Vettel clash as Ricciardo wins chaotic race
Vettel felt Hamilton had slowed down on goal and remonstrated his anger by pulling alongside the Brit and ramming into his auto . Vettel was unaware immediately after the race that his penalty was for swerving into Hamilton .
Speaking at the post-match presentation, Federer said: "It's been a hard year - we had a lot of practice, a lot of training, a lot of rehab to do, so it's nice to be back on the match courts and it feels great".
Earlier in the day, Petra Kvitova took a big step to convincing herself that she can make a full recovery when she reached the final of the Aegon Classic in Birmingham, England, by outplaying her exhausted friend and Czech compatriot Lucie Safarova. Federer served great, placing the first serves nicely, and he played against only 1 break point.
"So, I'm happy to react right away and let that be forgotten and actually move on and remind myself I actually can play well on grass".
However, the Swiss ace will have to get past the talented Zverev.
Nokia 6 comes to the U.S. with a taste of vanilla Android
BlackBerry is back in the smartphone space and Nintendo is bringing some of our favorite video game characters to mobile devices . According to media reports, the launch of the GST could lead to a delay of a few weeks in the launch of Nokia's new smartphones.
"I thought it was extremely close, especially that second set", Federer, who has never won a tournament nine times, told reporters.