Roger Federer maintained his 100% Laver Cup record against Nick Kyrgios on Saturday with a thrilling 6-7(5) 7-5 10-7 win over the Australian but Team World hit back in the doubles match later on to stay in contention for the title.

Playing in front of 17,000 fans in Geneva, home favourite Federer beat Kyrgios for the third time in as many editions before Rafa Nadal extended Europe's lead by beating Milos Raonic 6-3 7-6(1) in the night session.

"It was really close that first set so it was tough to lose," 20-times Grand Slam winner Federer said.

"The crowd could feel it, I could feel it. I needed to get some energy going but you can't do that if you don't play any good shots and Nick was playing very well.

"I was just trying to stay focused. If you can turn the momentum, the crowd gets back into it and I need some earplugs next time, it was just phenomenal."

However, Nadal and doubles partner Stefanos Tsitsipas were beaten 6-4 3-6 10-6 by Kyrgios and Jack Sock in the final match of the day as Team World narrowed Europe's lead to 7-5.

The first team to reach 13 points will be crowned champions, with each win worth three points on Sunday.

John Isner scored a 6-7(2) 6-4 10-1 win over German Alexander Zverev in the opening match of day two to help Team World draw level with Team Europe at three points apiece.

With two points up for grabs for victories on the second day of the tournament in Geneva, Zverev looked on course to extend Europe's 3-1 lead from Friday after edging a tight first set in the tiebreak.

However, the towering Isner battled back in the second set and broke to go ahead 5-4 with a lunging volley, then dragged the contest into a decider which he dominated.

"I wasn't making any inroads on his serve at all and he was the better player for 85% of that match," American Isner said.

"Of course, I got a little lucky at 4-4 but once I got up 5-4, I had a lot of momentum, and I think I showed that in the tiebreaker."