The Scots got the bonus point they wanted and more in Shizuoka and kept the opposition scoreless for the second straight game.
Scotland went down 27-3 to the Irish and was despondent. It responded by beating Samoa 34-0 and also blanking Russia. The Scots have scored 95 points without reply in their last two games.
Russia threw everything into its first three games in Japan and had nothing left in the tank at Shizuoka Stadium and was completely overrun. The Russians have still never won a Rugby World Cup game in eight attempts.
Captain Vasily Artemyev, who has started all eight of those losses at the World Cup, walked off to an ovation in the second half in what is probably his final game at the showpiece.
Scotland scored nine tries and had two more disallowed for forward passes. Scrumhalf George Horne had a hat trick and was denied a fourth because of one of the forward passes.
Flyhalf Adam Hastings, son of Scotland great Gavin, scored Scotland’s first two tries and kicked eight out of nine conversions for 26 points.
He was denied a hat trick in the last move of the game after a flowing attack from Scotland – one of many – ended with him dotting down between the posts.
That was also ruled out for a forward pass. It did not matter. Scotland did more than enough to show that Sunday’s game against Japan will be a humdinger, especially as most of Scotland’s best players had a rest on Wednesday evening.
Coach Gregor Townsend made 14 changes for this game, the most by Scotland between World Cup matches, and his reserves repaid him with an overwhelming performance.
Now for Japan in Yokohama.
The Pool A standings are: Japan top on 14 points, Ireland second on 11, Scotland third on 10. Ireland plays Samoa on Saturday and Scotland plays the hosts on Sunday in the fight for the two quarterfinal places.