'Irish avoid Shizuoka sequel but Boks blockbuster looms'

Ireland beat Tonga in their opening game of the 2014 World Cup in Nantes .

Head coach Andy Farrell says improvement is still needed before facing South Africa .

Ireland beat Romania in their warm-up game before taking care of the All Blacks in their opener on Sunday .

The Springboks will be waiting for Ireland at the Stade de France next week .

"We knew this one was coming down the pipeline," said Iain Henderson , who was not involved in Ireland 's 19-16 win over South Africa 10 months ago . "It's probably our biggest challenge in a good while. I think everyone's excited about it. Fortunately for us, we're able to get into the meat of looking at them this week . "All I can say is everyone is incredibly excited, irrespective of whether we'll be starting, on the bench or not involved. Everyone is buzzing.".