Surviving group of death will have prepared Japan for huge quarterfinal test against USWNT

The hope for Japan was always to advance from the group stage of the women's football tournament at the Paris Olympics -- but it was never going to be easy.

Drawn alongside reigning world champions Spain , perennial contenders Brazil and African powerhouses Nigeria , Japan knew they needed to be near perfect if they were to survive the 'group of death' -- even if there was a chance that finishing third could be enough to reach the quarterfinals.

In the end, near-perfection was exactly what Nadeshiko accomplished.

Having dropped their Group C opener 2-1 to Spain, the Japanese would bounce back in dramatic fashion as they scored twice in stoppage time for a thrilling 2-1 win over Brazil -- and followed it up on Wednesday with a 3-1 victory over the Nigerians that secured second spot in Group C.

Ultimately, they did not even need to rely on progressing as one of the two best-performing third-placed teams.

Yet, after making it out of the 'group of death', any hope Japan might have had that things could get slightly easier in the next stage after soon faded when it was confirmed that their next opponents will be none other than United States .

The record four-time champions of the FIFA Women's World Cup , United States have bounced back from a disappointing last-16 exit in the most recent edition of the tournament to loom as the legitimate gold medal contenders in Paris.

Having racked up three consecutive wins against Zambia , Germany and Australia to top Group B, the Americans also boast the most prolific attack with nine goals -- with new-generation talents Sophia Smith and Trinity Rodman shining alongside the more-experienced Mallory Swanson .

While theirs might not have been as daunting a group as Japan's, the USWNT still had their mettle tested against Germany and Australia and passed with flying colours.

United States will head into Saturday's quarterfinal as heavy favourites. There can be no denying that.

Nonetheless, it isn't exactly a foregone conclusion that they will cruise through and, for that, Japan have their earlier encounters to thank for.

Quite simply, Japan have proven -- most importantly to themselves -- that they can match it with the best, especially from their displays against Spain and Brazil.

After opting for a 4-4-2 against the Spanish, Nadeshiko coach Futoshi Ikeda switched to a back five against Brazil and it immediately made them harder to break down -- even coming up against opposition brimming with flair and panache.

While the win over the Brazilians ultimately came via a penalty by Saki Kumagai and a spectacular long-range effort from Momoko Tanikawa off a misplaced opposition pass, the attacking prowess of this perceived-conservative 5-4-1 system was on full display against Nigeria.

With increased attacking intent, the 5-4-1 effectively became an expansive 3-4-3 formation as Japan caused Nigeria all sorts of problems with their expansive passing -- dictated by the excellent midfield metronome Yui Hasegawa -- that looked to exploit the wide areas, with wing-backs Hikaru Kitagawa and Miyabi Moriya given license to bomb forward.

A change in personnel was also a factor as the Japanese fielded two out-and-out strikers for the first time in the tournament in Mina Tanaka and Riko Ueki , even if the latter was deployed in a wider, more withdrawn role.

The off-the-ball movement that has made Ueki so effective as a forward came to the fore when she beat the offside trap in the 22nd minute to race onto an incisive through-pass by Hasegawa and square the ball to leave Maika Hamano with an easy tap-in for the opener.

Tanaka, who was previously goalless despite offering the team tremendous endeavour and forward pressure, then got her just rewards when she opened her account at this Games on the rebound ten minutes later.

Then, Kitagawa -- featuring in the match-day squad for the first time in Paris -- rewarded Ikeda's faith in her by curling home a sublime freekick right before halftime to effectively put the result beyond doubt.

The fact that the players that were brought in performed admirably well should give Ikeda a welcome selection headache -- even if it is likely he will revert to some more-seasoned campaigners who were given a rest against Nigeria, and a more defensive approach, against United States.

Liverpool 's Fuka Nagano should come back into the engine room alongside Hasegawa, while Moeka Minami -- a teammate of captain Kumagai at Roma -- looks a likely reintroduction at the expense of the youthful Rion Ishikawa.

Tōko Koga , whose two appearances have come on either side of the backline, could also be included for more defensive stability even if both Kitagawa and Moriya would feel they have done well enough to retain their starting XI spots.

There are certainly many big decisions for Ikeda to make ahead what is looming as a tremendous test.

But for the challenges they have already faced -- and overcome -- at this Olympics and the lessons they have learned, both in terms of system and personnel, Japan are as well-equipped as they ever could be to pull off an almighty upset against the USWNT.