Rafael Nadal and Roger Federer are to donate A$250,000 (£132,570) to the relief fund in the fight against the Australian bushfires.
Raging fires have caused widescale damage across Australia and cast doubt over whether the Australian Open will be able to go ahead.
Practice was suspended until 11am at Melbourne Park on Wednesday morning and qualifying matches delayed for the second day in succession due to concerns over poor air quality caused by the ongoing crisis.
While play was cancelled out on the outdoor courts, tennis players from past and present came together for the Rally For Relief exhibition match at the Rod Laver Arena to raise money for those affected by the fires.
And world number one Nadal, 33, revealed after the match that he and Federer would be making their own separate donation.
"Talking with Roger a couple of hours ago, we decided to give $250,000 australian dollars together," Nadal said after the match.
"Hopefully that will inspire the people to support this terrible disaster that they're going through and we can help recover all the things we need."
Nadal and Federer join a long list of sport stars who have donated to assist those battling against devastating fires in Australia.
Fellow tennis stars Nick Kyrgios and Alex De Minaur, who come from Australia, pledged to donate $200 and $250 for every ace they hit during the ATP Cup.
Formula One champion Lewis Hamilton has donated $500,000, while Oscar-winning actor Leonardo DiCaprio gave $3 million to help the cause.
