Reuters reports that Novak Djokovic was lamenting a case of gastroenteritis after he lost his Australian Open quarter-final to France's Jo-Wilfried Tsonga.

The Serb had just won the third set to take a 2-1 lead and Tsonga looked deflated before Djokovic left Rod Laver Arena after he told chair umpire John Blom he needed to vomit.

While he managed to return, his game melted away and Tsonga ran out a 7-6, 6-7, 1-6, 6-3, 6-1 victor to set up a semi-final against Roger Federer, after the Swiss came from a set down to defeat Russian Nikolay Davydenko in four sets.

"I don't want to find excuses for my loss, but, you know, I went to vomit and I had diarrhoea before the match. After two games (of the fourth set) I had to go to the toilet. I couldn't hold on. There was no way, otherwise I would throw up on the court... just a terrible feeling."

Djokovic said he was unsure as to what had caused the sickness, as he had not eaten anything out of the ordinary.

The victorious Tsonga said Djokovic's illness was just part of the game.

"Sometimes it happens. … He had problems with his stomach... bad luck for him and good for luck for me."