The Sunwolves failed to pick up their first win of the Super Rugby season on Saturday in a 61-10 thrashing by New Zealand's Chiefs.

The Sunwolves went into their fifth game of the new campaign encouraged by a narrow 40-38 away defeat to the Lions in their previous outing, but quickly fell into a hole when the Chiefs scored four tries in the first 20 minutes at Prince Chichibu Memorial Rugby Ground.

Tries either side of halftime from Sunwolves debutant Semisi Masirewa and winger Hosea Saumaki gave the home side a glimmer of hope, but the Chiefs soon snuffed that out with five more tries before the final whistle to leave the Sunwolves winless heading into their first bye week.

"The team is very disappointed in today's performance," said Sunwolves head coach Jamie Joseph. "Once again we conceded early tries, and that then affects the team's confidence and morale. That's obviously not intentional, but it's Super Rugby and its happening far too often for us.

"The Chiefs are prolific counterattackers and have been among the best teams in the competition for the past six years. They've won the championship a couple of times. If you make a mistake, they make you pay. We made far too many mistakes and they made us pay."

Joseph made 10 changes to the team that lost to the Lions in Johannesburg, as travel fatigue caught up with a side that has already had to deal with several injuries this season.

"It's the first time that we've made selection changes to try to freshen up the team because of the amount of travel," Joseph said. "We have guys with jet lag still not sleeping.

"Super Rugby is unrelenting. We've come up against some tough teams in the first five games in this competition, and it's only going to get tougher."

The Sunwolves made a lively start to the match but their momentum was quickly checked when Tyler Ardron scored the Chiefs' opening try in the fourth minute.

All Black Brodie Retallick added another nine minutes later when his quick thinking caught the home team off guard, and the Sunwolves were again caught sleeping when Nathan Harris exchanged passes at a lineout to steal home for the Chiefs' third try.

"There were a few soft moments in the first half," said Sunwolves captain Willem Britz. "They scored three or four quick tries and we were just on the chase after that. Then we tried to have a go and made a few mistakes. When you play catch-up rugby, it's always difficult."

Solomon Alaimalo then crossed the line and Damian McKenzie kicked the conversion to put the Chiefs 28-0 ahead with only 20 minutes gone, and the home team's afternoon got worse when Saumaki had a try ruled out after a video replay.

The Sunwolves did manage to get on the scoreboard when Masirewa touched down in the 36th minute, however, and Saumaki got the second half off to the perfect start when he handed off Harris then ran half the length of the pitch for a try two minutes after the restart.

"I knew when I came up against the fullback one-on-one, I 100 percent knew I was going to score this try," said Masirewa, who came in as a late replacement for the injured Kotaro Matsushima.

But McKenzie nipped the Sunwolves' fightback in the bud with a try in the 45th minute, and further scores from Alaimalo, McKenzie again, Liam Polwart and Sean Wainui gave the Chiefs a thoroughly dominating victory.

"We've watched a lot of Japanese rugby over the last couple of years, and one of the things they do really well is the speed of ruck ball," said Chiefs captain Sam Cane. "They're very dangerous if they get that, so a focus of ours was to make sure we contested the breakdown.

"At the same time we like to play quickly as well, so I think it made for an entertaining game with a lot of breaks and a few tries. It was a pretty special occasion to be playing here in Tokyo. An awesome crowd and an awesome atmosphere."