Gustavo Kuerten beat Novak Djokovic 7-6, 7-5 in an exhibition match on Saturday.
What happened?
The match took place at Maracanazinho Arena in Rio de Janeiro, Brazil, with over 10,000 people in attendance.
Why it matters for Gustavo Kuerten
This win is a significant achievement for the 36-year-old former No. 1 in the world, who retired from professional tennis.
Gustavo Kuerten and Novak Djokovic also participated in the inauguration of a public court in the Rocinha shantytown on Friday.
What comes next?
Novak Djokovic will play football before a Brazilian league match on Sunday, alongside Serbian countryman Dejan Petkovic.
Former Brazil stars Romario, Bebeto, and Zico are expected to participate in the football match.
The exhibition match was played on clay, with Gustavo Kuerten emerging victorious in two sets, 7-6 and 7-5.
Novak Djokovic entertained the crowd by dancing and wearing a big wig to imitate Gustavo Kuerten's hairstyle.
The top-ranked Djokovic had recently won the ATP Finals title before facing Gustavo Kuerten in the exhibition match.