Zurich,  Swiss tennis great Roger Federer has become the first from his sport to top Forbes' list of highest paid athletes. With an estimated $106.3 million earned over the past 12 months, Federer edged out Portuguese football superstar Cristiano Ronaldo from the top spot.

The factors that went into Forbes' calculation were athletes' revenue, including prize money, salaries, contract bonuses, endorsements, royalties, and appearance fees from June 1, 2019, until June 1, 2020.

A key factor that went into Federer edging out the football stars was that the latter had to take heavy salary cuts during the coronavirus pandemic.

The three athletes immediately below Federer are all football players with Ronaldo on second with estimated earnings of $105 million. His arch rival and Argentine great Lionel Messi is third with an estimated $104 million while Brazil's Neymar comes fourth with $95.5 million.

NBA stars came next in the list with Los Angeles Lakers forward LeBron James earning $88.2 million, Golden State Warriors all-star Stephen Curry with $74.4 million, Brooklyn Nets superstar Kevin Durant with an estimated $63.9 million.

Japanese tennis star Naomi Osaka is the highest paid female athlete with $37.4 million. She however comes only 29th in the overall rankings. US tennis great Serena Williams comes 33rd with $36 million.