Novak Djokovic, Rafael Nadal and Sir Andy Murray all joined retiring Roger Federer for practice ahead of the Laver Cup.
The Big Four are teaming up for the first and last time to represent Team Europe in Federer’s final tournament at the O2 Arena.
The 20-time Grand Slam winner will play the final match of his career at the Laver Cup on Friday night, teaming up with long-time rival Nadal to say farewell.
Djokovic had played the 2018 Laver Cup with Federer in Nadal’s absence while Murray is making his debut at the team tournament this weekend.
All four of the tennis stars took to the court today to prepare for the upcoming action.
Serbian posted a picture of the big four with a caption saying: ‘Once in a lifetime experience to be on the same court with these legends and rivals.
‘Thank you for making it possible. Looking forward to a great weekend of tennis and a celebration of Roger Federer’s career.’
Former British No 1 Murray also tweeted: ‘Fun practice today.’
The Swiss superstar announced his decision to retire from the sport earlier this month, and this weekend’s event at the O2 Arena will be his swansong.
After having three major knee operations in recent years, Federer was always likely to only be fit enough to play doubles for Team Europe, and he had previously spoken of his desire to play alongside Nadal.
Team Europe captain Bjorn Borg has granted the 20-time grand slam champion his wish, and he will take to the court with Nadal, a 22-time major winner, to face Frances Tiafoe and Jack Sock of Team World at around 9pm on Friday.
‘I’m not sure if I can handle it all but I’ll try,’ said Federer, 41.
‘This one feels a whole lot different. I’m happy to have him on my team and not playing against him.
‘Playing with Rafa feels really different. To be able to do it one more time, I’m sure it will be wonderful and I’ll try my very best.
‘I’ll enjoy it but it will be very hard.’
Following the announcement of Federer and Nadal teaming up, ticket prices on re-sale sites have soared.
A single ticket is now being valued at £8,800 on Viagogo, with fans eager to get one last look at Federer before he bows out.
Federer and Nadal took to the court to practice in front of fans and media on Thursday, and the pair appeared in good spirits ahead of their highly-anticipated match.
For once, they were on the same side of the court, a slightly strange sight given their epic rivalry over the years.
They have faced each other 40 times, with their first meeting coming back in 2004. Nadal won that match and holds a 24-16 head-to-head advantage over Federer.
It was all smiles between the duo on this occasion as they delighted fans by going through their full array of groundstrokes and serves, with Federer showing no ill-effects of the knee problems that have troubled him lately.
Federer will be dreaming of ending his career with a fairytale win, but a stern test lies in store for him and Nadal as Tiafoe is coming off the back of making the US Open semi-finals, while Sock has won four grand slam doubles titles.
Earlier on Friday evening Andy Murray will take on Australia’s Alex De Minaur.