The win put Nadal one clear of Federer and world number one Novak Djokovic on the all-time Grand Slam titles race.
“What a match! To my friend and great rival, Rafael Nadal. Heartfelt congratulations on becoming the first man to win 21 Grand Slam singles titles,” 20-times Grand Slam champion Federer said in a gracious social media post.
“A few months ago we were joking about both being on crutches. Amazing. Never underestimate a great champion.
“Your incredible work ethic, dedication and fighting spirit are an inspiration to me and countless others around the world.”
Swiss Federer missed the Australian Open to continue his rehabilitation from knee surgery, while Djokovic was deported from Australia on the eve of the tournament due to visa issues involving his choice to forgo COVID-19 vaccination.
“I am proud to share this era with you and honoured to play a role in pushing you to achieve more,” added Federer.
“As you have done for me for the past 18 years.
“I am sure you have more achievements ahead but for now enjoy this one!”