Australian tennis great Rod Laver led the charge of tributes on social media following Roger Federer's historic 20th grand slam win.
The 11-time grand slam winner was seen snapping pictures of an emotional Federer on his phone soon after his stunning win and later uploaded one to his Twitter account.
"Surrounded by greats, past and present - @rogerfederer, Neale Fraser, Ashley Cooper and Roy Emerson," Laver wrote with accompanying pictures of Federer and his fellow Australian tennis legends.
In the minutes after Federer's five-set win over Croatia's Marin Cilic, the 79-year-old also tweeted "Emerson. Djokovic. Federer. 6 x Australian Open crowns apiece. Astonishing then, incredible now."
Federer tweeted a selfie of himself with the Norman Brookes Challenge Cup with a trophy emoji, the No.20 and a love heart emoji as the tributes flowed.
"Congratulations Roger- the GOAT!!!" tweeted 18-time grand slam winner Martina Navratilova.
"Grand slam number 20 for @rogerfederer! Just unbelievable. A truly superhuman effort!" added former Wimbledon champion Pat Cash.
Swiss president Alain Berset reportedly telephoned Federer as he made his victory tour to offer his personal congratulations.
Federer's impressive performance under extreme pressure from Cilic also earned the admiration of Indian cricket great Sachin Tendulkar.
"Grace, power and agility. No one in the world could play that shot. @rogerfederer #AustralianOpen2018 #AusOpen," he tweeted.
The Swiss master was typically emotional in victory, tearing up as he made his acceptance speech.
"Nobody makes me cry like Roger Federer...no one... there is no one like him..." 18-time grand slam winner Chris Evert wrote.
"He was so close to making it through the speech without crying! I'm crying now too" wrote former world No.5 Eugenie Bouchard.
Federer isn't ruling out returning to Dubai next month with the chance to usurp Rafael Nadal as world No.1.
Federer's successful Australian Open title defence has left the 36-year-old within striking distance of the top ranking.
Victory in the Dubai Open starting on February 27 would catapult Switzerland's 20-times grand slam champion above Nadal, making him the oldest world No.1 in tennis history.
