Ireland survived some brilliant attacking Japanese play to gain revenge for their shock 2019 World Cup defeat with a 39-31 win in an entertaining and free-scoring match at the Aviva Stadium on Saturday.
While Ireland struck first and outscored the visitors by three tries to two to lead narrowly at the break, the scoreline did not tell the tale of a half which Japan dominated for long periods and played some breathless rugby.
The visitors regained the lead after a second superb assist from the boot of fly-half Yu Tamura, but Ireland continued to make the most of every opportunity with Josh Van der Flier and Jacob Stockdale breaking the tit-for-tat scoring before Naoto Saito finished off another brilliant team effort for the visitors.
Japan began to tire and a more controlled Irish second-half limited any further opportunities with Joey Carbery -- whom Irish fans will be delighted to see play a full 80 minutes -- kicking Ireland into an eight-point lead they comfortably saw out.
Ireland were without several injured players and shorn of other regulars who are on tour with the British & Irish Lions in South Africa.
The Irish play the United States in Dublin next Saturday, while it is now back-to-back defeats for Japan in their first fixtures since losing to South Africa in the quarterfinals of the World Cup they hosted two years ago.
They also lost 28-10 to the British & Irish Lions last weekend.