LEVERKUSEN, Germany -- The Big Three of women's soccer might not be eager to expand, but they might not have a choice.
Japan, fourth in the FIFA rankings behind the U.S., Germany and Brazil, put on a dazzling display of precision passing and faultless finishing to beat Mexico 4-0 on Friday in front of 22,291 appreciative fans in Bayer Leverkusen's home stadium.
Homare Sawa, who played in both U.S. professional leagues over the past 10 years, had a hat trick on only four shots. The team completed 488 passes, more than any other team in this tournament has even attempted.
All this against a Mexican team that frustrated an experienced England side in a 1-1 opening draw in this tournament and beat the U.S. in World Cup qualifying.
And yet coach Norio Sasaki thinks his team is capable of better.
In May, after the U.S. beat Japan 2-0, Sasaki said his team was roughly 60 percent ready for the World Cup. Are the players at 100 percent now that they've clinched a quarterfinal berth?
"They are not 100 percent ready yet even today," Sasaki said as he looked ahead to a group-stage finale with England. "There are mistakes in terms of passing or coordinating the play. They are not familiar enough with the pitches yet. These are the issues we have to clear, but we've been improving. We were better against Mexico [compared to a 2-1 win over New Zealand]. It's an ongoing process."
New Zealand coach John Herdman paid tribute to Japan's skill after the teams' match Monday in Bochum, saying the Japanese keep the ball better than other teams in the tournament. Mexico's Leonardo Cuéllar also offered praise.
"It's an excellent team," Cuéllar said. "I definitely feel they're going to be one of the contenders in this World Cup."
Like Brazil, though the Brazilians didn't show it in their opening match, Japan can produce mesmerizing strings of passes, such as the long sequence that led to Sawa's third goal in the 80th minute.
Japanese players also are capable of individual efforts, such as Shinobu Ohno's goal, in which she sliced through defenders Natalie Garcia and Natalie Vinti, former University of San Diego teammates who aren't used to being beaten as a tandem.
Like Germany, Japan has a mix of experienced players such as Sawa and Aya Miyama, who set up Sawa's other two goals on a free kick and a corner kick, alongside young talent like Mana Iwabuchi, who helped Japan break a deadlock against New Zealand but wasn't really needed in this game.
Like the United States and Germany, Japan is building through top-flight club soccer at home.
"That's the best, to have a women's league on a permanent basis," Sasaki said. "In the Japanese women's football leagues, the style is always a constant, and that's true for the training."
And yet Japan can bring together several influences.
"Several players from Japanese women's leagues are playing in the European leagues or the Western leagues, and that is helping them improve the quality of performance, and that is enhancing the characteristics of the national team players, and they are assimilating with each other," Sasaki said.
Japan still has one potential weakness that no amount of training can fix: It's the second-shortest team in the tournament behind Mexico. Sawa scored twice on headers, but she wasn't outleaping anyone and certainly won't do so against the likes of the U.S. or Germany.
But to beat the Japanese players in the air, someone will have to get the ball away from them. And if Japan ever reaches that 100 percent level of readiness, that will be a tall task.
Japan will always be a threat on set pieces like free kicks and corner kicks even without aerial prowess. Miyama is a wizard against defensive walls, notching two assists from set pieces against Mexico and hitting the winner against New Zealand.
That weapon is an effective deterrent against opponents' fouls. Lashing out in frustration while Japan plays keep-away is a bad idea. And that leaves Japan free to do what it does best: knock the ball around and wait for the perfect opportunity to strike.
"In the first half particularly, I think my players were able to express their own style of football playing," Sasaki said. "I think the result is there because of that."