Swiss tennis legend Roger Federer played his final match alongside Rafael Nadal in the Laver Cup on Friday at O2 Arena in London, and the duo fell 6-4, 6(2)-7, 9-11 loss to American duo Frances Tiafoe and Jack Sock.

Federer, a 20-time Grand Slam champion, announced his retirement from professional tennis on Sept. 15, revealing the Laver Cup would mark his farewell from the sport. He said in a post on his social media accounts (h/t ESPN):

"As many of you know, the past three years have presented me with challenges in the form of injuries and surgeries. I've worked hard to return to full competitive form. But I also know my body's capacities and limits, and its message to me lately has been clear.

"I am 41 years old. I have played more than 1500 matches over 24 years. Tennis has treated me more generously than I ever would have dreamt, and now I must recognize when it is time to end my competitive career."

Friday's match was full of excitement and felt like the whole world was watching.

After a back-and-forth battle with the first set tied 4-4, Federer and Nadal combined to win the next two games and claim the set. Federer played an easy volley to bring up set point and took charge with a forehand shot that was too hot for Sock to handle.

The second set came down to a tiebreak, and Tiafoe and Sock came out on top to force a third set, winning the tiebreak 7-6 (2) as Federer was forced into an error.

The third set saw a great battle between the two sides, but Tiafoe and Sock proved to be too much for Federer and Nadal.

Down 9-8, Tiafoe fought back to tie the set 9-9 before responding to a Federer serve with a thunderous forehand return winner to give the Americans a 10-9 lead. With match point and Sock serving, the two teams engaged in a lengthy rally before Sock ended the match with a forehand winner to the corner.

While Federer lost, he still goes down as one of the greatest tennis players of all time. He competed in more than 1,500 matches, winning 103 singles titles and 20 Grand Slams in his storied career.

Federer is the second tennis great to enter retirement of late, joining Serena Williams, who retired after the US Open earlier this month.