Roger Federer and Rafael Nadal were on the same side as part of Team Europe facing Team World at the Laver Cup in Prague.
Europe won the contest 15-9, and the most exciting moment was when the pair played as doubles partners on the second day of the competition.
The two tennis icons, who have won an amazing total of 35 Grand Slam titles between them, were on the same side of the net for the first time in history on Saturday.
Despite the lack of team chemistry, they managed to defeat the American duo Sam Querrey and Jack Sock 6-4, 1-6, 10-5 to give Team Europe a 9-3 lead in the contest.
It was exciting for fans to see how two of the best players of this era would gel and collaborate.
And, an interesting video has emerged that shows how they discuss team tactics before the match.
It worked, although it was more due to the individual greatness both of them posses.
Both admitted they had not practiced together and Federer is positive it will stay like this in future.
However, the pair enjoyed being on the same side and learned some valuable things about each other.
"We will always be rivals as long as we are active. And after this we will be rivals again," Federer commented.
"It’s been an absolute pleasure sharing the court with Rafa. Being on the same side of the net you know you can trust him in the big moments.
"Seeing his decision making and his thought process was very interesting."
Nadal described the experience as "unforgettable", and added: "To have the possibility to have Roger next to me is a huge privilege... something I wanted to make happen at some point and today I made it happen.
"After all the history that we had behind us as rivals it was great to be on the same side of the court fighting for a team it was something we enjoyed a lot." the Spaniard added.
"The atmosphere for the whole match and during the weekend was fantastic."
Although Federer and Nadal played down the possibility of competing in doubles, their opponent Sam Querrey is positive they would be contenders to win majors.
"I do think if they played together consistently, they would definitely be [contenders] for four slams a year," the American insisted.
Bearing in mind their qualities as singles, it is exciting to imagine seeing them as partners on the court more often.