Novak Djokovic and Naomi Osaka leave Melbourne with the big silverware after claiming the men's and women's titles at the Australian Open.

For Djokovic it was a ninth title from as many finals, while Osaka lifted a grand slam trophy for the fourth time at the end of a challenging fortnight for players and organisers.

Here, the PA news agency picks out five things we learned.

Putting on tournaments is hard

Australian Open organisers can breathe a huge sigh of relief and sleep for the first time in months. The tournament made it to its conclusion and, most importantly, it was not the source of any outbreaks of coronavirus in the Melbourne community. But staging the event has come at massive cost. With limited fans allowed – and none during a five-day lockdown – plus the great expense of providing charter flights and funding quarantine, tournament director Craig Tiley estimated losses would amount to around 100million Australian dollars (approximately £56million), wiping out Tennis Australia's surplus and forcing them to take a loan. Although the vaccine roll-out offers significant hope that times will soon be easier, for now putting on a tennis tournament is akin to running a marathon while jumping over hurdles.

Djokovic still reigning

Was it a wave goodbye or a see you next year? Only Serena Williams knows whether the lingering look she gave Rod Laver Arena after her semi-final defeat by Osaka had any greater significance. What was very clear was how much the defeat hurt, with Williams leaving her post-match press conference in tears. At 39, it is obvious that time for her to win that much-coveted 24th grand slam singles title is running out. But Williams really is not far away, and the improvements she made to her fitness and movement during the off-season bode well for the rest of the year.

Tennis needs Kyrgios

Love him or hate him, and there are plenty in both categories, it is impossible to ignore Nick Kyrgios. His willingness to shoot his mouth off is distasteful at times but also refreshing in a sport where too many players are afraid to express an opinion that might earn them negative headlines. And on court he brings an energy and excitement that no one else can match. His matches against Ugo Humbert and Dominic Thiem were dramatic and captivating – the latter was the most watched non-news programme on TV in Australia this year. Whether he fulfils his talent or not, the sport is undoubtedly more interesting for his presence.