The Laver Cup was a tremendous success last year and it is proving another massive hit with tennis fans at the hard indoor court of the United Centre in Chicago.The format sees Team Europe take on Team World in the three-day tournament with some of the very best within the sport showcasing their talent and genius.Saturday saw Roger Federer take centre stage once again, having suffered a surprise defeat alongside Novak Djokovic in the doubles on Friday night.This time he took on Nick Kyrgios, who always seems to thrive playing in a team environment.The Aussies, competing in his first singles match of the cup, was trailing the Swiss ace 6-3, 3-1 when he hammered a serve in the direction of the ad court and it was initially called out.The official immediately realised he had made a mistake, however, and overturned the call.The Aussie youngster headed towards the chair umpire John Blom, who opted to replay the point rather than award it to Kyrgios, with Federer barely getting his racket on the serve.“So, you’re telling me [the umpire] called it before Roger hit it?,” Kyrgios questioned the umpire, who replied with a distinct “Yes!”“You are delusional,” quick came the reply from the Australian tennis star.The situation boiled over further when Team World captain John McEnroe came into the scene.The American legend didn’t hold back in letting the umpire know what he thought of the decision.McEnroe interrupted: “Wait a minute. Wait a minute. “You’re gonna say that that affected his return?”The umpire responded: “Well, that’s questionable.”Raising his voice, the 59-year-old yelled: “In your opinion, you think that affected his return?” to which the umpire then replied: “There was a small chance.”“What, 0.01?”, a disgruntled McEnroe remarked.Umpire: “I don’t know the number, but there’s a small chance, so we replay the point.”

We haven't seen McEnroe take that tone with an umpire for a long time.

Federer went on to win the match 6-3, 6-2 to give Team Europe two more points to take their tally to 7-1 at that moment.

The day, however, ended with Team World managing to narrow the lead to 7-5, winning the following two ties.