Shizuoka - Scotland will have to be "spot-on" when they take on Japan on Sunday for a place in the Rugby World Cup quarter-finals, coach Gregor Townsend has warned.

The Scots, with Adam Hastings shining at flyhalf, notched up a nine-try, 61-0 drubbing of winless Russia on Wednesday to ensure a mouth-watering showdown with the hosts in Yokohama next week.

Japan are unbeaten in their three Pool A matches, having notably claimed the shock scalp of Six Nations giants Ireland.

"All aspects of our game have to be spot-on against Japan," Townsend said, underlining that his team had to make the best use of the ball when in possession against what he called a very well drilled Japanese outfit.

Scotland opened their campaign with a 27-3 defeat by Ireland before rebounding to rack up an impressive 34-0 victory over Samoa.

"The Ireland game is already in the history books, it was a missed opportunity where we didn't get our best game in place," Townsend said.

"You move on to the next game and what the players have done since that Ireland game, I couldn't ask any more of them.

"It's two games now we haven't conceded a try or even a point, which is very encouraging."

Townsend added: "If we hadn't got the bonus point, Sunday would have been more difficult."

The former flyhalf rested a quintet of front-line players in Greig Laidlaw, Finn Russell, Stuart Hogg, Blade Thompson and Johnny Gray as he juggles his 31-man squad on a punishing four-day turnaround for the Japan game.

"It's always been in our schedule," Townsend said. "It's a challenge, we know the opposition have had a good rest going into the game.

"It's really important we recover well tomorrow... and do our best to play our best rugby Sunday."

Townsend said Scotland would be in close touch with World Rugby as a typhoon bears down on Japan, threatening to disrupt the weekend's games. Scotland could be eliminated if Sunday's game with Japan is cancelled.

"We'll be getting updates from World Rugby over the next two days as to what contingencies are," he said.

Russia coach Lyn Jones said he wouldn't know who to bet on between Japan and Scotland.

"If I had 10 yen, I wouldn't know who to go for on the night!" the former Wales flanker joked.

"Scotland have speed and skill and if they can put pace on Japan and get outside...

"But Japan are so well drilled, they're an incredibly difficult side to play against.

"It's going to be a hell of a game!"

Jones said Russia exited the tournament with their heads held high despite previous defeats by Japan (30-10), Samoa (34-9) and Ireland (35-0).

"It's been a huge success as a late inclusion into the tournament," Jones said, describing Tier One rugby as "supersonic".

"The level is another sport for Tier Two nations."

But Jones insisted that the experience of playing in a World Cup was invaluable to his players.

"We're going to benefit from this and we look forward to the future with some optimism, we can only get better," he said.

"The physical potential in Russia is unlimited," Jones said. "It's a sleeping bear, a sleeping giant, we need to shake it awake."