'I've got goosebumps': Tennis world unites for incredible $5m bushfire gesture

A full house at Rod Laver Arena has watched Roger Federer defeat Nick Kyrgios in a one-set finale to the Australian Open's Rally for Relief to aid bushfire charities.

The 20-time grand-slam winner took on Kyrgios as the centrepiece of Wednesday night's event and prevailed 7-6 (8-6).

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Stars including Rafael Nadal, Serena Williams, Novak Djokovic, Caroline Wozniacki, Stefanos Tsitsipas and Alexander Zverev also played Fast Four doubles at the event that helped to raise almost $5 million.

"I've got goosebumps ... everyone came together and it's just an amazing feeling," Kyrgios said. "It's been an emotional couple of weeks.

Roger Federer and Nick Kyrgios pose with firefighter Alistair Mason at the Rally for Relief. (Photo by WILLIAM WEST/AFP via Getty Images)

"When I was back home in Canberra, I couldn't even go outside (due to bushfire smoke) ... and I'm just so happy that we had Roger, Rafa, Novak - some of the greats - to get behind this.

"The awareness has grown and I think we're doing everything we possibly can to overcome this."

With select firefighters and emergency personnel looking on from courtside seats, Kyrgios saved two set points before Federer prevailed in an entertaining encounter.

The six-time Australian Open champion and world No.3 moved well, ahead of his 20th assault on the season-opening grand slam at Melbourne Park.

Naomi Osaka, Serena Williams, Caroline Wozniacki and Stefanos Tsitsipas also took part. (Photo by WILLIAM WEST/AFP via Getty Images)

Kyrgios and Federer emotional over bushfire crisis

But a competitive hit-out wasn't really his goal.

"What I wanted to do was raise awareness, raise money and tell people to still come and travel to Australia because people probably think around the world that you can't right now," Federer said.

"That was the idea.

"And to have some fun, have a hit with Nick ... we get along very well.

"We've had some epic matches over the years and this was fun ... it wasn't about winning and losing."

The Swiss master also dipped into his own pocket, combining with Nadal to make a $250,000 donation, with fundraising efforts to continue during the Australian Open.