Top seed and world number one Rafael Nadal en route to the last 16 of the Australian Open ©Getty Images

World number one and top seed Rafael Nadal reached the last 16 of the Australian Open in Melbourne today in far easier fashion than his long-time rival Roger Federer had in the previous day’s nightcap.

Nadal, 33, who is one short of Federer’s all-time men’s record of 20 Grand Slam singles titles, earned a 6-1, 6-2, 6-4 win over fellow Spaniard Pablo Carreño Busta, the 27th seed, to maintain his challenge for what would be only his second Australian Open title.

That sole win came in 2009 over his perennial Swiss opponent, who only a few hours earlier had teetered on the brink of an exit before winning fluctuating third-round tie against unseeded home player John Millman 4-6, 7-6 (7-2), 6-4, 4-6, 7-6 (10-8).

The 38-year-old Swiss trailed 8-4 in the first-to-10 super tie-break operating at this event before winning six points in a row to send the 15,000-capacity crowd at the Rod Laver Arena into a ferment.

"What a match,” was Federer's verdict.

“John deserves half of this - he made it so difficult for me.

"He deserves all the support, he is a great story and a great fighter."

Australia's Nick Kyrgios earned a last-16 Australian Open match against world number one and top seed Rafael Nadal - whom he mocked earlier this week - after a five-set win over Russia's Karen Khachanov ©Getty Images
Australia's Nick Kyrgios earned a last-16 Australian Open match against world number one and top seed Rafael Nadal - whom he mocked earlier this week - after a five-set win over Russia's Karen Khachanov ©Getty Images

Nadal will now meet the mercurial home player who openly mocked his idiosyncratic - and to many, irritating - serving style earlier in the tournament, Nick Kyrgios, whom he has previously criticised for showing insufficient respect.

Kyrgios, seeded 23rd, showed once again the high level of his talents when fully concentrated as he beat Russia’s 16th seed Karen Khachanov in an epic five-setter 6-2, 7-6 (7-5), 6-7 (6-8), 6-7 (7-9), 7-6 (10-8).

Germany’s seventh seed Alexander Zverev also reached the last 16 with a 6-2, 6-2, 6-4 win over Fernando Verdasco of Spain.

Before and after Nadal’s victory that same Rod Laver Arena had witnessed two upsets in the women’s tournament which, if not as striking as the previous day’s dismissals of third and eighth seeds Naomi Osaka and Serena Williams, were nevertheless significant.

Second seed Karolina Plíšková of the Czech Republic lost her third round match against Russian 30th seed Anastasia Pavlyuchenkova 7-6 (7-4), 7-6 (7-3) and then fifth seed Elina Svitolina of Ukraine was beaten 6-1, 6-2 by a renascent, but unseeded, Garbiñe Muguruza of Spain.

Muguruza, formerly world number one but now ranked at 32, won the French Open in 2016 and Wimbledon the following year, but has since struggled to find consistent form.

After losing in the first round at Wimbledon last year the 26-year-old Venezuelan-born player split from her coach, Sam Sumyk.

She will now meet ninth seed Kiki Bertens of The Netherlands, who beat Zarina Diyas of Kazakhstan 6-2, 7-6 (7-3).