It was the first time the two had ever played each other in an official match (they met at the Kooyong exhibition last weekend), so seeing them stand side by side, separated only by a net, was quite a sight. At 211cm, the Croatian is more than a ruler's length taller than Goffin (180cm). If it was a physical clash of two men; it was David v Goliath. Well, except, David was seeded higher.

Highlighting the difference in physical make-ups of the two was their clothes.

Karlovic was dressed in a fluorescent yellow top, with matching shoes, socks and hat. You wouldn't lose him in the dark.

The Belgian, on the other hand, was dressed conservatively in an all navy kit, with dark socks and black shoes, with only a hint of yellow. Then it's the way they play.

Karlovic is a renowned serve-and-volleyer, for obvious reasons. His big serve is difficult to penetrate, and before you know it the ominous big man is charging towards the net to finish the point off.

But that played largely into Goffin's hands. The compact  Belgian chases down almost anything and makes his opponents work hard to win points, and he rarely makes mistakes. And that's largely how the entire match panned out. It ended up being a procession.

Goffin made just two unforced errors on his way to a 6-3 first set win, where he continually passed the incoming Karlovic at the net. The big Croatian couldn't find an answer and the match was over before he knew it, losing the final two sets 6-2, 6-4 in a match that lasted less than 90 minutes, repeating the dose of a week earlier at Kooyong. In total, Goffin made just five unforced errors compared to Karlovic's 28.

"Yes, I was worried to fight until midnight," Goffin said with a smirk, admitting he was not expecting to win as easily as he did.

"The score came as a bit of a surprise. I knew I had all the weapons in my racquet to beat Ivo, but not in straight sets.

"I was ready for a lot of tie-breaks also, but I'm happy in the way I broke him."

The 26-year-old from Rocourt is in career-best form, finishing 2016 at a career-high ranking of 11, making him the highest ranked male player from Belgium in history.  A win in the fourth round on Monday would equal his career-best performance at a grand slam, matching his efforts in last year's French Open.

To do that, he'll have to get past no. 8 seed Dominic Thiem of Austria, who shot up the rankings after reaching last year's semi finals of the French Open.

Thiem had little trouble in defeating Frenchman Benoit Paire in four sets; 6-1, 4-6, 6-4, 6-4 in a touch under two and a half hours.

The 23-year-old last year became the youngest player to make the top 10 since Milos Raonic back in 2013.

Thiem and Goffin know each other well, having played on seven occasions, with the Belgian holding a narrow 4-3 lead.