The host nation were made to work hard in two of the three sets before eventually prevailing 25-22, 25-16, 27-25.

Miyashita's superb serving always appeared too much for the Dominican side to handle, with Nagaoka capitalising by picking up 21 points in little more than two sets of action.

Japan are still not guaranteed qualification despite the victory, but Dominican Republic now have no chance of making the Games despite a plucky effort.

Japan are now one of four teams have won four times and lost just once after five matches.

Italy's unbeaten record was ended by The Netherlands, who produced a superb performance to win 25-21, 25-21, 25-14.

Both sides are now tied for the lead, along with South Korea, who beat Peru 25-22, 25-14, 25-21.

Thailand overcame Kazakhstan 25-18, 25-19, 25-15 in today's other game.

Thailand and Peru lie joint fifth on two wins and three defeats.

A penultimate round of matches will take place tomorrow.

The eight team round-robin tournament is doubling as a Rio Asian qualifier - with the best performer from the continent automatically qualifying for the Games regardless of where they finish.

The best three other countries will also advance.

Elsewhere, a second four-team qualification tournament began in San Juan, Puerto Rico, with only the group winners booking an Olympic spot.

The hosts cruised past Algeria, 25-10, 25-11, 25-12, while Colombia began by seeing off Kenya 25-14, 25-15, 25-13.