Japan kept pace with a strong World XV side before succumbing in the second half to lose 45-20 in a warmup for the Rugby World Cup on Saturday.

The World XV arrived for the game at Prince Chichubu Memorial Ground led by South African World Cup-winner Bakkies Botha and packed with hungry Australian fringe players hoping to force their way into the Wallabies squad for next month's World Cup.

But it was Japan that scored the first try through Karne Hesketh, and only the boot of World XV fly half Berrick Barnes kept the visitors in front with the score at 19-7 at halftime.

The World XV began to stretch their legs in the second half, however, with 194-cm, 123-kg winger Taqele Naiyaravoro finishing the match with three tries and scrum half Andrew Ellis scoring two, as Japan managed only one penalty try in response.

The defeat was Japan's fourth in a row after losing three times at last month's Pacific Nations Cup, but coach Eddie Jones remained upbeat with time running out before the World Cup begins in England next month.

"In terms of our World Cup preparation, it's excellent," said Jones. "We had a problem at the PNC in terms of our discipline in defense, and that was evident again today. At the PNC we had a problem with the breakdown.

"So they are the two main areas we need to fix. Can we fix them in the next four weeks? I'm positive we can. So the result is disappointing, but in terms of the World Cup preparation, we are still moving along well."

Japan rounds off its World Cup preparations with games against Uruguay in Fukuoka on Aug. 22 and again in Tokyo the following Saturday, before taking on Georgia in Gloucester, England, on Sept. 5.

Japan then opens its World Cup campaign in Pool B against two-time champion South Africa on Sept. 19 before facing Scotland, Samoa and the United States, and former Springbok Botha believes the Brave Blossoms are now better prepared to face his countrymen.

"It was definitely a test match for us," said Botha, who retired from international duty in November last year after 85 tests. "When you pull this jersey on we've got respect for each other, respect for our opponents and we showed it tonight.

"We asked as many questions as we wanted to, because that's our job when we play international sides like Japan. I know they are in a pool with South Africa, and I think we prepared them very well for the first game against South Africa in the World Cup."

Two Barnes penalties staked the World XV to a 6-0 lead, but Japan soon hit back with the first try of the match.

The Brave Blossoms dug in to work their way toward the visitors' goal line near the left touchline, then spun the ball all the way out to the other wing for Hesketh to touch down in the corner. Ayumu Goromaru added the conversion.

The lead did not last long, as Naiyaravoro cut loose to restore the World XV's advantage. The hulking winger received the ball from No. 8 Pierre Spies, then shrugged off a Japanese tackle to canter over the line.

Barnes slotted the conversion before adding two more penalties to take the World XV into halftime on top.

Japan returned fire with a Goromaru penalty nine minutes after the restart, but the visitors stretched their legs when scrum half Ellis profited from a lucky bounce to score a try in the corner, awarded after a TV replay.

Ellis scored again just minutes after another Goromaru penalty. Naiyaravoro bludgeoned his way down the wing before passing the ball to Christian Lealiifano, who handed it off to Ellis to stroll over the line.

Japan checked the World XV's momentum with a penalty try in the 68th minute, driving at the visitors down the right side before referee Andrew Lees awarded the score.

But Naiyaravoro scored two more tries to give the final scoreline a more emphatic slant in the visitors' favor, and Jones could do nothing but admit that his side had been beaten by the better team.

"They were a good side today," said Jones. "You can't take away from that. They assembled a very strong team with some old guys who really put in today, and some young guys playing for World Cup spots.

"I'm proud of my team's effort today, but we really need to start learning. I expect to start to see that against Uruguay in the next couple of weeks."