Federer linked up with Alexander Zverev in the doubles in the first match on Sunday only to go down to defeat to Jack Sock and John Isner.
That gave Team World an 8-7 lead – the first time in Laver Cup history that their side had been ahead in the tournament.
Zverev cut a nervy figure in the doubles and it was up to Federer to restore Team Europe’s advantage with a thrilling win over Isner in the singles.
Federer had to come from behind – and stave off match points – to take the win in one of the matches of the year so far.
He admitted afterwards: “I’m not sure if I wanted it to be that exciting! What a match, what a weekend.
“Thank you Chicago, that’s it. I can’t thank you enough.
“Regardless of what happens it’s been a successful weekend
“I couldn’t be more excited about what’s to come now. The Laver Cup is here to celebrate tennis and have a great weekend and for everyone to enjoy themselves.
“I think we’ve had that except maybe for John, who I feel sorry for.
“He’s had a wonderful weekend himself so it’s just been terrific throughout. I can’t thank you enough everybody and I appreciate it.”
Team Europe need just one more win from the final two games to take the title.
Team World, meanwhile, need both Kevin Anderson and Nick Kyrgios, against Novak Djokovic in the last match on, to come out on top.
Source : EXPRESS