Wales beat Fiji 29-17 in a thrilling contest in Oita on Wednesday to secure a quarter-final place.

Nakarawa, 31, is playing at his third World Cup and believes his side lost to one of the 2019 tournament's leading contenders.

"Nothing is impossible for them," said the 2018 European Professional Rugby Player of the Year.

"If they believe they can win the World Cup, they can win the World Cup.

"They have already been number one in the world, so it's possible that they can win the World Cup."

Fiji gave Wales an almighty fright in Oita, racing into a 10-0 lead early in the match with a typically flamboyant display, brimming with flair and invention in attack while brutally physical in all aspects of their play.

Nakarawa set the tone by freeing his arms from a Hadleigh Parkes tackle to produce a basketball-style offload to a team-mate in the build-up to Josua Tuisova's opening try.

Wales looked rattled at that point but they eventually composed themselves to take the lead, which they lost again early in the second half before pulling clear to secure a bonus-point victory.

"We shocked Wales in the first half and we could see it on their faces they were shocked," said Racing 92's Nakarawa.

"We played well in the second half but then they showed why they're one of the top five sides in the world.

"They got the number one spot last month and they showed why."

This was a fourth successive World Cup in which Wales had faced Fiji.

They suffered their only defeat against the Pacific Islanders in the 2007 tournament, a chaotic loss which knocked Wales out at the pool stage and led to the sacking of head coach Gareth Jenkins.

Since then, however, Wales have won every match against Fiji.

And although the Fijian squad in Japan was comprised of some of the most impressive individual talents on display at the World Cup - Nakarawa, Tuisova and Semi Radrada among them - they paid a heavy price for failing to take their opportunities.

Fiji had three tries ruled out for forward passes, while two yellow cards - the same as Wales - undermined their bid to cause an upset.

"It's those kind of small things on a big stage like this," added former Glasgow player Nakarawa.

"It seems small, but it's moments like that which cost you in games like this.

"Wales played really well. They capitalised on our mistakes, our errors and mostly our indiscipline."

Despite taking the lead in their opening match against Australia before eventually succumbing to the Wallabies, Fiji's defeat against Wales left them with only one win from their World Cup campaign.

That came in comprehensive fashion against Georgia, but Fiji were left to rue a shock loss against Uruguay which effectively ended their hopes of reaching the quarter-finals.

"It was a great effort, but that's rugby," said Nakarawa.

"Win or lose, it's not the end of the road and we'll come back stronger.

"For us it's all over now. We'll go back and come back stronger for 2023.

"I want to wish the Wales team all the best for the rest of the World Cup."