The two-time Grand Slam champion failed to find his form throughout the contest but still looked as though he may squeeze through to round four when he took a 4-1 advantage in the third set.

Delbonis, the current world number 53, held firm, though, and hauled himself back into the match before he completed a surprise 6-4, 4-6, 7-6 triumph.

“I have had a couple of big wins, but in this situation it was special," the Argentinian said.

“For that tournament, for that surface, for me is the best win.”

Switzerland’s Stanislas Wawrinka, seeded third, had no such problems as he booked his place in the fourth round with a straight sets win over Andrey Kuznetsov of Russia.

Wawrinka, winner of the 2014 Australian Open and the French Open the following year, proved too strong for the unseeded Russian as he emerged with a 6-4, 7-6 success.

He will be joined in round four by sixth seed Tomas Berdych of the Czech Republic, who made light work of Croatia's Borna Ćorić, progressing thanks to a 6-1, 7-6 victory.

Berdych’s compatriot Denisa Allertova, who accounted for Australian Open winner Angelique Kerber of Germany in the last round, was unable to continue her run in the women's competition as she was beaten by Britain’s Johanna Konta.

The Australian-born Briton has been enjoying the season of her career to date having reached the semi-finals of the event in Melbourne in January and maintained her superb form by dispatching the Czech 6-4, 6-1.

The 25th seed will go on to face Czech Karolina Pliskova, who overcame former world number one Ana Ivanovic of Serbia 6-2, 6-0.

Italian ninth seed Roberta Vinci is also through after she breezed to a confident 6-1 6-3 victory over Ukraine's Elina Svitolina.

Belinda Bencic of Switzerland was another high-profile casualty as she was knocked out following a 4-6, 6-3, 3-6 defeat to Slovakia’s Magdaléna Rybáriková.