BILLY Vunipola was unaware of the potential importance of his bonus-point clinching try in England's 35-11 World Cup-opening victory over Fiji.

The Saracens number eight came off the bench and barged over for England's fourth try to earn five points for a less-than-convincing victory in a tight Pool A, which includes Wales and Australia.

"To be truthfully honest with you, I didn't know that bonus points counted in the World Cup," Vunipola said.

"I was just more excited that I'd scored a try. It's always good to get over for your country.

"I'm just happy we won and we move on to the next game."

The build-up is over and England have just a week to improve on their display before Wales visit Twickenham.

There was relief and satisfaction among the ranks.

"I don't think you feel the nerves and tension until you step out on the field and all the expectation comes crashing back down on you," Vunipola added.

"It's a home World Cup, first game up against a team with nothing to lose. It was tough, very nervy, but it's very satisfying to come away with a win."