Japan fell behind against Germany on Wednesday, with Ilkay Gundogan scoring from the penalty spot in the 33rd minute, but two substitutes turned it around for Moriyasu's team, with Ritsu Doan levelling the scores in the 75th minute before Takuma Asano won it with a brilliant finish in the 83rd minute.
Samurai Blue have now put themselves in a strong position to reach the next round of the competition, and they have previous when it comes to advancing through the group stage.
Indeed, Japan have progressed to the round of 16 on three previous occasions, including back in 2018, when they finished second in Group H before losing to Belgium in the first knockout round.
Moriyasu's side will finish their campaign against Spain on December 1, so there is no downplaying the importance of this match, especially as Costa Rica will enter it off the back of a thumping loss to Spain.
Japan progressed to the finals of the 2022 World Cup by finishing second in Group B, picking up 22 points from their 10 matches, which left them one point behind the leaders Saudi Arabia in the Asian qualification section.
Costa Rica have faced Japan on five previous occasions in international football, with all five fixtures proving to be non-competitive games, and Japan have recorded four wins, including a 3-0 success in September 2018.
Los Ticos are competing in the finals of the World Cup for the third time in a row, and they incredibly reached the quarter-finals of the 2014 competition, topping Group D ahead of Uruguay, Italy and England before overcoming Greece on penalties in the first knockout round.
Costa Rica saw their tournament ended by the Netherlands in the last eight, but it was a brilliant performance from the Selection, who beat New Zealand in the intercontinental playoffs back in June to ensure that they would be present in the 2022 edition of the competition.
Luis Fernando Suarez's side were the final team to advance to the World Cup, but they suffered a 7-0 defeat to Spain in their competition opener on Wednesday.
Ferran Torres scored twice, while Dani Olmo, Marco Asensio, Gavi, Carlos Soler and Alvaro Morata were all on the scoresheet for La Roja in Doha, with Costa Rica struggling against Luis Enrique's side.
La Tricolor will take on Germany in their final match in the section on December 1, and it is difficult to imagine them making an impression in this group, but they will be determined to give their supporters something to cheer against Japan.
Hiroki Sakai is a doubt for Japan due to the injury that he picked up against Germany, and he was forced to miss training on Thursday with the issue.
Takehiro Tomiyasu would be Sakai's natural replacement, although the Arsenal defender also missed training on Thursday, so he will need to prove his fitness over the next 24 hours or so.
Asano came off the bench to score the winner against Germany, and he could now come into the starting side for this match, potentially taking the place of Daizen Maeda.
Yuto Nagatomo was also replaced in the second half of the team's first match of the tournament, but the 36-year-old is fit to start this game, and he should again line up at left-back.
Costa Rica, meanwhile, have not reported any injury concerns from their defeat to Spain.
Head coach Suarez is expected to resist the temptation to shuffle his pack from the loss to La Roja, but there could be a change at the back, with Kendall Waston potentially coming in for Carlos Martinez.
Bryan Ruiz and Alvaro Zamora are also among those pushing for spots in the side, but Joel Campbell should again be joined by Anthony Contreras in the final third of the field, and there is no question that the manager will be looking for a much-improved performance in this contest.
Japan possible starting lineup:
Gonda; Tomiyasu, Itakura, Yoshida, Nagatomo; Endo, Tanaka; Ito, Kamada, Kubo; Asano
Costa Rica possible starting lineup:
Navas; Waston, Calvo, Duarte, Oviedo; Tejeda, Borges; Bennette, Fuller; Campbell, Contreras
We say: Japan 2-0 Costa Rica
Japan were brilliant against Germany on Wednesday, and it is really difficult to look past them when picking a winner here. Costa Rica should show improvement from their defeat to Spain, but we are fully expecting Japan to make it back-to-back wins in the section courtesy of a 2-0 scoreline.
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