The win was nervier than it should have been having raced into a 4-0 second set lead, winning six games in a row but Brady broke Osaka and then served out to make it 4-2.

Osaka lived dangerously in that seventh game, twice clipping the net to lose points but she held on to make it 5-2 and put the pressure back on Brady’s service.

Brady, who was in hard quarantine ahead of the tournament, held on but the impetus by then was with Osaka at 5-3 to serve for the championship. She did so to love with Brady hitting long to seal the win.

By contrast, the first set at Rod Laver Arena was an even tougher test. Osaka took the first set 6-4 but Brady had taken the game to the Japanese world No 3 after a sluggish start.

Crowd favourite Osaka won the toss and started the stronger but control of the first set wavered in windy conditions at Melbourne Park.

The 23-year-old Osaka broke Brady to make it 3-1 but Brady broke right back then held serve to make it 3-3, Osaka twice hitting into the net to give up the game.

The 25-year-old American had rallied back to level it at 4-4 and showed some of the tennis that got her to a first career slam final.

Brady earned another break point after a wonderful lob that saw the crowd get behind her but Osaka’s talents were on full display in the next point to take the scores to deuce. Advantage Osaka. Game Osaka. 5-4.

The 22nd seed, who Osaka beat on the way to winning the US Open last year, then gave up easy points to allow the 2019 Australian Open champion to go a set up.

Osaka is now undefeated in four slam final appearances and two-time winner at both the Australian and US Opens. She follows Monica Seles as the only woman to win their first four slam finals in the Open era. Seles won her first six.

Victory in Melbourne is the ideal start to the year in which Osaka will hope to win the Tokyo 2020 Olympic Games gold on home soil.

“Hello everyone,” Osaka started her acceptance speech. “Firstly, I wanna – do you like to be called Jenny or Jennifer? – firstly, I’d like to congratulate Jennifer.”

Osaka was full of praise for her opponent after the win, while Brady had already described Osaka as an inspiration for young girls.

“We played at the semis of the US Open a couple of months ago,” Osaka said. “I told anyone who would listen that you were going to be a problem and I was right.

“For me it’s really hard to play you and to see your growth over the last few months is really incredible for me to see.

“I know for me my team is like my family so I am sure you guys have a lot of really cool adventures together to congratulations to you guys as well.

“I think we’re going to play a lot more matches so here’s to that.

“I’d like to thank my team. I’ve been with them too long – a month and some change – and we’ve been through quarantine together

“This one’s for you.

“Lastly but not leastly I’d like to thank you guys,” she told the fans in the stands. “Thank you for coming and watching.

“It feels incredible for me. I didn’t have my last grand slam with fans. Just to have this energy it really means a lot. Thank you so much for coming.

“Thank you for opening your hearts and you arms toward us. For sure I feel like playing a grand slam right now is a super privilege and is something I won’t take for granted. Thank you for this opportunity.

“Thanks to the ball kids and volunteers. Craig Tiley, the tournament director, everyone for making this tournament possible and hopefully we’ll be back next year.”