MELBOURNE, Jan 23 (Reuters) - Jo-Wilfried Tsonga strayed on to dangerous ground when he suggested jokingly that women tennis players were "emotionally unstable" compared to the men after losing his Australian Open quarter-final on Wednesday.
The Frenchman's defeat to Swiss world number two Roger Federer at Melbourne Park meant the top four men's seeds reached the semi-finals at a grand slam for the 15th time in the professional era.
While the seventh seed was clear in his mind why the top men dominated, he quickly realised he was on shakier ground when asked why the same was not the case in the women's game.
"You know, the girls, they are more unstable emotionally than us. I'm sure everybody will say it's true - even the girls," he told a news conference to laughter, before adding when women journalists disagreed: "No? You don't think?"
"It's just about hormones and all this stuff," he added, a big smile on his face. "We don't have all these bad things, so we are physically in a good shape every time, and you are not. That's it."
Women's world number three Serena Williams, renowned for her toughness on court, would have begged to differ with Tsonga after a painful back injury contributed to her loss to fellow American Sloane Stephens in the last eight earlier on Wednesday.
Tsonga was completely at a loss, however, when asked to explain why he could play such a close five-set match against 17-times grand slam champion Federer and yet not break the cabal of the "Big Four" in men's tennis.
"To be honest, I have no idea," he said. "You know, if you have some advice for me, I will take it because I don't know. I don't know what is the difference.
"I'm just working hard. I do my best. I mean, that's it. Maybe I'm less talented for the moment.
"In tennis, you know, you cannot lie," he added. "If they are number one, number two, number three, number four, it's because they deserve it and because they are the best players at the moment."
The 27-year-old gave as good as he got for most of an absorbing three-and-a-half hour contest with Federer on Rod Laver Arena before losing 7-6 4-6 7-6 3-6 6-3.
His defeat, along with Jeremy Chardy's loss to Andy Murray earlier in the day, means France will have gone three decades without a male grand slam champion by the time this year's French Open begins.
Tsonga came as close as any Frenchman has to ending the drought since Yannick Noah's 1983 win at Roland Garros when he lost to Novak Djokovic in the 2008 Australian Open final.
Despite being unhappy at his defeat to Federer, he said he would be straight back to work to prepare for his next attempt to break into the winners' circle at one of his sport's majors.
"I'm a bit in the bad mood because I lost it," he said. "But in other ways I played a good match. I was solid. I was there every time.
"I keep my level of concentration really high at all times. I just gave my best today, so I'm proud of that. I'm not happy to lose, and I already look forward for the next tournament, the next grand slam, to try another time." (Editing by Clare Fallon)