And it is now the case that Australia's highest ranked player, Lleyton Hewitt, is lower down the computer print-out than Japan's No 1.
That is half down to the fact Hewitt is at his lowest position for a decade, and also because of the rise and rise of Kei Nishikori, a 19-year-old from Shimane, a town close to Hiroshima, and a young player with plenty of talent in that racket-arm.
It is not going to be long before Nishikori, who was No 59 on last week's list, is a top-50 player.
Japan's tennis culture and traditions are not nearly as strong as Australia's, so you can imagine the excitement felt here by the crew of Wow Wow, the wonderfully-named television network from Japan, especially as Nishikori could play the bookmakers' favourite, Andy Murray, in the third round.
Murray is sponsored by the likes of Highland Spring; Nishikori has a 'Cup Noodle' patch on his arm. They can't get enough of Nishikori back in Japan.
Nishikori was just 18 years old when he won the Delray Beach title last year by beating American James Blake in the final, making him the youngest man to score a tournament victory on the tour since Hewitt in 1998.
Later in the season, he made the fourth round of the US Open, and this Australian Open will only be his third grand slam tournament.
Even so, Nishikori is already close to achieving the highest ranking in history by a Japanese male, as last Monday's list had him just 13 places behind Shuzo Matsuoka's peak of No 46.
Nishikori's father, Kiyoshi, is an engineer, and his mother, Eri, is a piano teacher, but as soon as Kei picked up a racket at the age of five it was obvious that he had some tennis talent.
When Nishikori was 14, and when he couldn't speak a word of English, he moved to Florida to train at the Nick Bollettieri Academy, and such was the enthusiasm there for him to break Matsuoka's record that he was referred to as 'Project 45'.
"I hope to become the highest ranked Japanese man in tennis history this year. I've been surprised at how quickly I have moved up the rankings. I couldn't believe it when I won Delray Beach. That was the biggest jump for me." said Nishikori, who only turned 19 last month.
"I get a lot of attention in Japan. I get a good feeling from that. I live in the United States, and only go back for two months a year, and it's unbelievable the attention I get.
"In Tokyo and the other big cities, I always have people coming up to talk to me, to take pictures of me. Baseball and soccer are the most popular sports in Japan, but I hope I can make tennis more popular back home, I guess. It's getting more popular already. All the kids are starting to play, and maybe that's because of me."
One concern for 'Project 45' ahead of his first-round match against Austria's Jurgen Melzer is that he has some soreness in his arm. But he hopes he can make it past Melzer.
Maybe then he could set up a possible match with Murray. "I like Murray's tennis," said Nishikori. "Murray can do almost anything."