The Polish qualifier is the man of the moment having claimed his fourth top 20 scalp in a row after beating German Philipp Kohlschreiber, Croatian Marin Cilic, Briton Andy Murray and Serbian Janko Tipsarevic, his quarter-final victim on Friday.
Asked if he slept well after eliminating world number three Murray in the third round after saving a match point on Thursday, Janowicz told reporters with a grin: "I could sleep, no problem. I slept very well two hours, so no problem to sleep whatsoever.
"I stayed on my computer for a few hours. I just went to sleep at 5:00. I just was not able to sleep this night, but as I can see, it doesn't matter if I sleep.
"I don't eat. Right now I'm playing best tennis of my life, and I hope tomorrow I can play even better," he added.
While the eighth-seeded Tipsarevic was booed for retiring exhausted when trailing 3-6 6-1 4-1, Janowicz enjoyed the support of the Paris crowd.
But it is unlikely to last as the world number 69, who started the year outside the top 200 but will feature in the top 40 on Monday, next faces local favourite Gilles Simon.
Janowicz was not fazed by the prospect of facing a partisan crowd.
"Yeah, tomorrow I will play against a French guy, but mentally I'm a really tough guy," he said.
"I remember in my match against Andy Murray in Great Britain during the Davis Cup three years ago, the whole crowd was against me, over 5,000 people.
"Actually I didn't really care. I just was focused on my game, and I hope I will be able to do the same tomorrow."
Even with an empty stomach, Janowicz will fight. He is used to it.
"I was bad boy at school, primary school. High school I was fighting with everyone, with teachers. I was a really bad guy," said the Pole, who is still looking for sponsors.
"Somehow it's really not easy for me to explain why I'm that kind of guy, why, for example, yesterday I played against Andy Murray and I didn't feel pressure at all."
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