While many of his Japanese teammates showed signs of nerves during the Rugby World Cup opener on Friday, wing Kotaro Matsushima was on song from the start and focused on keeping his pre-match hat-trick promise.

"Some of my teammates were getting too tense or trying too hard. I had fun from the start and did not have any awkward nerves," Matsushima said following the match against Russia in which he scored three tries in his team's 30-10 win.

"The experience of playing (wing in all four of Japan's matches) at the previous World Cup helped," he said.

Teammate Ryoto Nakamura revealed before the match that Matsushima, who entered the tournament having scored at least one try in five of his last six games, told him he was eying a World Cup hat-trick.

"It was on my mind, but after Nakamura told everyone, I had to go for it," the man of the match said. "I was looking at the bigger picture and could communicate with the guys inside about where the space was."

Matsushima, who became the first Japanese player ever to score three tries in a World Cup game, said he should have finished with even more five-pointers than he did.

"I saw that some Russian players were getting tired, putting their hands on their knees, so I should have scored more, especially in the second half," said Matsushima, who was born in Pretoria, South Africa, to a Japanese mother and Zimbabwean father.

"If I play at that level in the next game it will be very tough (against a team like Ireland)," Matsushima said.