Denis Shapovalov has claimed Rafael Nadal receives special treatment from umpires after an epic Australian Open quarter-final tussle between the pair, an assertion the Spaniard rejects.

Shapovalov fell short of an incredible comeback against the record-chasing Nadal, who prevailed 6-3 6-4 4-6 3-6 6-3 after more than four hours of action on Rod Laver Arena.

The match was full of tension, with Shapovalov furious that Nadal escaped a time violation for taking too long between the first and second sets.

After umpire Carlos Bernardes refused to call time on Nadal's changeover, Shapovalov lost his temper, bursting out: "You guys are all corrupt."

The players subsequently met at the net for a discussion, but Shapovalov was frustrated again when, before the deciding set, Nadal left the court for a medical timeout having struggled with a stomach issue, but then also had a toilet break.

Asked post-match if he felt Nadal received preferential treatment, Shapovalov said: "Of course. 100 per cent he does. 100 per cent. Every other match that I have played, the pace has been so quick because the refs have been on the clock after every single point.

"I'm completely ready to play and the clock is ticking 3, 2, 1, clicking towards zero.

"I'm looking at the umpire and obviously I'm going to speak up and say something.

"I've been ready to play for a minute and a half, and he tells me he's not going to give him a code violation because I'm not ready to play. To me, it's a big joke if somebody says that.

Shapovalov added: "I respect everything that Rafa has done and I think he's an unbelievable player. But there have got to be some boundaries, some rules set.

"It's just so frustrating as a player. You feel like you're not just playing against the player; you're playing against the umpires, you're playing against so much more."

When these comments were put to Nadal he responded: "No. Not in that case, no, no."

"I really believe that on the court you don't deserve better treatment than the others. I really don't want it and I don't feel I have it.

"Without a doubt, even as everybody knows, I have a huge respect for Carlos and I think he's a great umpire. Is it not the case that he was always hard with me on court, no?

"I really believe that it's always in the mind that the top players get bigger advantages. And on the court it's not true. That's my feeling. I never feel that I had advantages on the court, and I really believe that he's wrong in that case.

"I honestly feel sorry for him. I think he played a great match for a long time. Of course, it's tough to accept to lose a match like this, especially after I was feeling destroyed and probably he felt that, [but] then I was able to manage to win the match.

"I wish him all the very best. He's young, I think we all make mistakes on our careers. I made a lot of mistakes too when I was younger, and probably he will understand later on after he thinks the proper way that probably he was not right today."