Rafael Nadal has become the most successful man in tennis history by winning the Australian Open and his 21st Grand Slam title.

He took on Daniil Medvedev in a gruelling five-hour and 24-minute marathon - the second-longest in the tournament's history - to clinch the trophy.

At the winning moment, Nadal dropped his racket to the court in disbelief, before pumping his fists and celebrating with his support team.

The victory also makes him only the second man in the Open era after Djokovic to win each of the four titles at least twice, with Nadal finally adding a second Australia Open crown to the one he claimed in 2009.

Speaking after his win, Nadal congratulated Medvedev: "This has been one of the most emotional tennis matches of my career and to have shared the court with you is just an honour. All the best in the future."

He continued: "If I'm honest, a month-and-a-half ago I didn't know if I would be able to be back on the Tour and playing tennis again, and today I am here in front of all of you with the trophy next to me.

"You really don't know how much I fought to be here. I can't thank everyone enough for all of the support I received since I arrived here in Australia, it's been amazing. Thank you so much for all of the support.

"The support that I have received is going to stay in my heart for the rest of my life."

He said although he had feared this could have been his last Australian Open: "Now, there's plenty of energy to keep going so thank you very much... I'm going to keep on trying my best to keep on coming and be here next year."

It is a remarkable achievement, given Nadal feared a couple of months ago he may have to retire due to a chronic foot problem.

Reaching the final had already exceeded expectations of what Nadal could achieve and at first, it appeared he would fall short after Medvedev moved two sets ahead.

Most of the build-up focused on the historic significance of the Spaniard bidding for his 21st Grand Slam but he found himself under pressure from the start.

Nadal began to play more offensively in the second set and twice managed to break the Medvedev serve.

The match was temporarily halted when an intruder made their way onto the court, waving a banner highlighting refugee detention and jumping down from the crowd.

He was only metres away from Medvedev but was tackled by security men and hauled out of the arena.

Medvedev - who is rapidly becoming the sport's favourite villain - was greeted by boos as he entered the Rod Laver Arena.

He became increasingly wound up by the crowd, with appeals to the umpire to control the "idiots", but kept a handle on his emotions a better than he had during his semi-final victory over Stefanos Tsitsipas, when he screamed at umpire Jaume Campistol.

His mood was not improved when he double-faulted to drop serve in the third game of the fourth set and, although he got back on terms immediately, Nadal took his seventh break point in the next game.

Rod Laver, winner of 11 Grand Slam singles titles called it a "final of Herculean proportions".

He wrote on Twitter: "Two AO crowns and 21 majors, given everything you have endured this historic victory is so special Rafa. It has been a privilege to watch you doing what you love. Congratulations."

The victory comes as Ashleigh Barty made history by becoming the first player to win the Australian Open on home soil in 44 years.

The world number one defeated American Danielle Collins in the final, claiming the women's singles titles.