Carlos Alcaraz lashed out at organisers of the Paris Masters after he suffered a shock defeat at the hands of Ugo Humbert.

World No 2 Alcaraz was the highest-ranked player in the tournament after Jannik Sinner was forced to withdraw due to a virus, but he suggested the rapid pace of the court in Bercy made it impossible for him to play his best tennis.

Alcaraz has complained about the fast conditions in Paris after his first match against Nicolas Jarry, before he was beaten 6-1, 3-6, 7-5 in front of an exuberant Paris crowd who cheered on the Frenchman to the stand-out win of his career so far.

While Alcaraz is generally respectful both in victory and defeat, he failed to contain his annoyance after the match as he suggested the conditions in Paris made it impossible to play his best tennis.

"This court… I mean, I don't want to say something that there is going to sound like an excuse," said Alcaraz.

"First of all, Ugo deserves to win, that's obvious, but it depends. Because I play, for example, the Davis Cup indoor court and the court was way slower than this one.

"When I played the first match, the stats came out that it is the fastest court in the Masters 1000, probably on the tour right now. This is crazy. I don't know. Probably and the fastest one, you know, in the last ten years in this tournament.

"So I don't know why they do it. I don't know why they have changed a court from other tournaments and obviously in the same tournament, comparing to other years.

"It surprised me a little bit, so I came here with not too many days. Probably I had to come earlier to get used to these conditions but I didn't. But, honestly, all I can say is I don't understand why they did it."

Alcaraz also suggested he should have arrived in Paris a little earlier to get used to the conditions as he added: "I mean, it is very difficult to play in these conditions.

"For me, for my level, I try to change up as much as I can to this court, to this speed. I thought that it suits pretty well to my game, but it doesn't.

"When I play against someone like Ugo that he doesn't let you get rhythm into the match, he plays probably, every time at his 100%, really flat. So I couldn't play good tennis.

"I practice at home but it isn't the same court that I thought. So I didn't surprise about my level, about my game, but I was surprised about everything a little bit."

A jubilant Humbert had a very different verdict on a thrilling evening in Paris, as he saluted the most memorable victory of his career.

"It's the most beautiful victory in my career, and it's the best moment I lived on a tennis court. It's incredible," said the world No 18. "I train for that. I practice for that. This is what I repeated to myself in the third set.

"I didn't want what happened last year to repeat itself. I also thought about the match against Zverev, and it made me stronger.

"This is what I love about tennis. I don't want to make any predictions or tell you what's going to happen. I try to live the moment to the full.

"I came to Bercy to live this kind of emotion, this kind of match. When it's like that, anything is possible. I don't know how far I'll go, but it's a question I don't want to answer."