Scotland's Townsend optimistic Japan showdown will go ahead

* New Zealand-Italy match also cancelled

* Scotland hope match will go ahead with Japan

HAMAMATSU, Japan, Oct 10 (Reuters) - Scotland coach Gregor Townsend is optimistic the weather will clear sufficiently after Typhoon Hagibis passes through to ensure his side's must-win clash with Japan goes ahead in Yokohama on Sunday.

He said his understanding of the rules was that the day of the match could not be changed. But he said had also been told "things can change" if a force majeure is declared under "exceptional circumstances", and he did not know whether that could yet make Monday a possible date.

Rugby World Cup organisers took the unprecedented step of cancelling the England-France clash in Yokohama and New Zealand-Italy game in Toyota City on Saturday because of the expected destructive effects of the typhoon.

With the storm expected to have passed through by Sunday, a decision on the Pool A clash between the tournament hosts and Scotland would not be made until the morning of the game.

"We believe that the game hasn't been cancelled because the weather will be better on Sunday and it looks like the game will be played," Townsend told reporters in Hamamatsu.

"That's what we have to put faith in, that they have made that call with a lot of certainty and confidence that the game will be played on Sunday night."

Tournament regulations state that cancelled games are ruled a 0-0 draw, with two points going to each team, which would end Scotland's hopes of reaching the quarter-finals.

Townsend's side need to win the game, preferably with a bonus point, to ensure they advance.

The host nation would qualify for the quarter-finals for the first time if their match in Yokohama is called off.

Townsend said that early indications of the typhoon were that it might not hit Yokohama until Sunday and that World Rugby had mentioned the possibility of moving the match.

Scottish media reported the team had been quietly hoping for a shift to Kobe if that was the case.

"Maybe yesterday, when it looked like the weather was going to be rougher on Sunday, there seemed to be discussion about looking at an alternative venue," Townsend said.

"The way I read the rules was you can't change days, but you could change venues – contingencies would be in place.

"I have since been told there is force majeure (rule), that things can change because of exceptional circumstances," he said. "If that means Monday because it takes a day for things (infrastructure) to be put back in order, then who knows.

"But just now I think they are planning for it to go ahead on Sunday," he said.

(Reporting by Greg Stutchbury in Toyota City, Japan; Editing by Timothy Heritage)