Rafael Nadal and Roger Federer are two of the best singles players tennis has ever seen.
Between them, the pair have ranked up 167 career titles. Impressive stuff.
However, that doesn’t mean that there weren’t teething problems during a doubles game in the Laver Cup against Sam Querrey and Jack Sock.
In fact, one particular moment had commentators chortling.
Renowned on the singles court, they maybe they still had to get used to each other on the same court.
The pair both went for the same ball - Federer had called it - but 'King of Clay' Nadal cheekily stole the shot.
Eventually the pair won the match 6-4, 1-6, 10-5, handing the European team an unassailable 9-3 lead.
Following the match, Spaniard Nadal said that playing alongside Roger Federer was an unforgettable historic day.
"It was an unforgettable day, after the history behind us to be on the same part of the court fighting for the team is something we enjoyed a lot.”
Nadal’s view was echoed by Federer, who said that it was a great moment of his career, telling journalists after the game that: "For me, personally, it is a great moment too.
“We only ever practised once together, back at the World Tour Finals, so we don’t show each other a lot.
“We will always be rivals. But this was something very special, it was an absolute pleasure being on the court with Rafa and seeing his decision-making process.
"I understand that people only expect a win from us, but it’s very complicated, we’re playing indoors against the big servers, and I hadn’t played doubles for so long, I was trying to remember what to do.
Watch their altercation below.
"The two of us getting together, our two fan groups having to get together, that was interesting too. It was a success, but this isn’t just about us.
“The celebration of Rod Laver and having John and Bjorn there over-rides the doubles, but this was still an important moment for us."
It will be a sad day when these two retire from tennis, that’s for sure.