Two goals in quick succession in the first half were the ultimate difference between the two teams but this was not a Fifa Women’s World Cup clash where the winners ever looked in doubt.
Japan made it two from two in Group C with a professional display in front of 6992 fans at the covered stadium.
They jinked and jived and did most things at a reasonable clip.
At the back, they snuffed out nearly everything that came their way, preventing Costa Rica from having a single attempt on target until the 82nd minute.
Japan’s dominance extended to possession (57% to 43%), shots (23 to six) and corners (nine to zero).
It became apparent, early in the clash at the rechristened Dunedin Stadium, that this was going to be a long and difficult night for the Costa Ricans.
Japan, World Cup champions as recently as 2011 and fresh off a 5-0 win over Zambia in the opening round of this tournament, looked utterly dominant and full of enterprise in the final third.
The Japanese poured forward in waves in the opening quarter and probably should have banked an early goal or three.
Much of the action went through slippery forward Minami Tanaka and she had the best initial opportunity with a reasonably clear header.
Costa Rican goalkeeper Daniela Solera was then called into action when she made a smart save from the firm header of 138-game Japanese veteran Saki Kumagai.
It really should have been 1-0 after 15 minutes but two Japanese players collided after a rebound left the goalmouth wide open.
Spiky defender Fabiola Villalobos tried manfully to keep Costa Rica in the game, and Solera was mostly sound, but there was a sense of inevitability when Japan finally opened the scoring.
Alert midfielder Hikaru Naomoto pounced on a defender’s slip, drove into the box and lanced a crisp left-footed shot through the hands of the diving Solera.
That goal had been coming, and the second took barely 120 seconds to arrive.
Aoba Fujino did it all herself, tracking away from the goalmouth to regain possession, beating a defender, cutting to the byline and threading a perfect shot that beat Solera at the near post.
That made it six different scorers of seven goals for the Japanese, who could go far in this World Cup if they maintain that sort of scoring balance.
Tanaka blazed over shortly before halftime and, if there was one minor niggle for Japan at the break, it was that they should really have been a couple more goals to the good.
The first 20 minutes of the second spell were relatively subdued.
Japan then seemed to sniff a third goal when replacement Riko Ueki chased a lofted ball into the box and collided with Solera, leaving Villalobos to play the rescue game before nearly hoofing the ball into her own net.
Hinata Miyazawa, who scored twice in the demolition of Zambia, had a good look with a volley from the edge of the box, but could not find the target.
The match ebbed and flowed in the final 15 minutes. Costa Rica looked comfortable on the ball without really threatening, while Japan just tidied up as necessary, though Miyazawa might have done better with a very late opening.
The Japanese complete group play with a game against Spain in Wellington on Monday, and Costa Rica head to Hamilton to play Zambia.
Fifa Women’s World Cup
The scores
Japan 2
Hikaru Naomoto 25’, Aoba Fujino 27’
Costa Rica 0
Halftime: Japan 2-0
