Prague, Sep 24 Spain's Rafael Nadal and Switzerland's Roger Federer, arguably the two greatest tennis players of all time, had done just about everything in their sport prior -- except play doubles on the same side of the net. They finally did so here on Saturday in the star-studded Laver Cup team event and defeated Americans Sam Querrey and Jack Sock 6-4, 1-6, 10-5 to give Team Europe a 9-3 lead over Team World at the end of the competition's second day, reports Efe news agency. Cheered on by most of the 20,000 fans in attendance at Prague's O2 Arena, Federer and Nadal used their guile and all-court skill to overcome a second-set hiccup and edge their big-hitting rivals. "It was unforgettable for both of us after the history we have behind us as rivals. Something we really enjoyed a lot," Nadal, a 16-time Grand Slam champion, said about playing with his 19-time major champion arch-rival. Federer, who has faced the Spaniard in nine Grand Slam finals (with Nadal holding a 6-3 edge), echoed the sentiments. "For me personally it was a great moment too. After this we'll be rivals again, thank God or unfortunately, but this was something very special." Team Europe came into the Laver Cup as the heavy favorite and that squad has lived up to expectations; after leading 3-1 heading into Saturday, the Europeans stretched their advantage to six points with a pair of singles wins by Federer and Nadal and the doubles triumph. Team World got two points on Saturday thanks to Australian Nick Kyrgios' come-from-behind 4-6, 7-6 (7-4), 10-6 victory over Czech Tomas Berdych. The Laver Cup features a unique format in which three singles and one doubles match will be played on each of the three days and the points received per match victory increase every day (one point per match on Friday, two points per contest on Saturday and three points per match on Sunday). The first team to reach 13 points will win the inaugural Laver Cup, with a doubles decider to be played if the teams are tied at 12 points apiece at the end of Sunday's matches.