Scotland head coach Gregor Townsend has questioned an "incredible call" from referee Jaco Peyper that resulted in Rugby World Cup Pool A rivals Japan securing a bonus-point win over Samoa.

Townsend's men have two pool games remaining and sit nine points adrift of the tournament hosts, who they face on Sunday in what is likely to be a shoot-out for qualification.

Japan are top with a three-point cushion over Ireland after Kotaro Matsushima's last-gasp score gave them a bonus point in the 38-19 win over Samoa on Saturday.

Townsend believes Japan, who are hoping to reach the last eight for the first time, were fortunate to be awarded a late penalty for a crooked Samoa put-in, which led to their fourth try.

"Look, I think it is an incredible call," said Townsend.

"It's not something that's been referred and there's an agreement there is more latitude for the scrum-half putting the ball into the scrum because you are the team who has won the scrum.

"To see it in the World Cup really surprised me. To see it come in added-on time was an even bigger surprise.

"It was a call I've not seen for a long time in the game."

Wing Darcy Graham is the only player to retain his place in the Scotland team to face Russia in Shizuoka on Wednesday.