CJ Stander has admitted Ireland's Grand Slam bid against England is now the biggest game of his career.
The Munster loose forward insisted he appreciates the significance of helping Ireland chase just a third-ever Six Nations clean sweep, especially on St Patrick's Day and at Twickenham.
Ireland claimed a record 11th consecutive win with Saturday's 28-8 victory over Scotland, and that proved enough to swipe the title a week early as England lost 22-16 to France in Paris.
Former South Africa Under-20s star Stander swapped Super Rugby's Blue Bulls for Munster in 2012 after Springboks coaches told him he was too small to be a Test-match flanker.
Six years on he has a British and Irish Lions cap, helped Ireland claim a maiden win over New Zealand - and now has the chance to drive Joe Schmidt's men to a first Grand Slam since 2009.
Asked if Saturday's Twickenham showdown is now the biggest game of his career, Stander replied: "Yes, for sure; there's an opportunity to create something for ourselves as a group.
"Some of us, it's their first Six Nations, some of us have been here for a few years.
"Preparation wise, put the head down, make sure you train well and get into the team for Saturday.
"It's a great opportunity. You set goals for yourself at the beginning of the year and on a personal level you strive to be part of that.
"Now we've got an opportunity and we've got to make sure we rest up and get ready for next week.
Allied to setting a new all-time national win record, Kiwi coach Schmidt has now guided Ireland to three Six Nations titles in just five years.
100% record at home for the guys. Another brilliant performance. The grand slam dream is well and truly alive. CJ Stander celebrated in style (see photos). #IREVSCO #IREvSCO #NatWest6Nations pic.twitter.com/Mpk4YgSiXz— AVIVA Stadium (@AVIVAStadium) March 10, 2018
Stander has become an Ireland mainstay under Schmidt since qualifying on residency and making his debut in the 2016 Six Nations.
The 27-year-old has always spoken candidly about his decision not to accept the Springboks' attempts to convert him into a hooker, believing him too small to cope as a Test back-row forward.
But now with 22 Ireland caps under his belt in the back-row, Stander feels his decision more vindicated than ever, even though he knows some may never agree.
Asked if opportunities like chasing a Grand Slam with Ireland only serve to add more credence to his original decision to leave South Africa, Stander said: "Yes but at the same time a lot of players make a lot of sacrifices.
"I lost a lot of friends and coaches along the way so it's good to give them something back.
"We said as a group we wanted to achieve something. That was probably in the back of our minds, we've played well in the last few games, got lucky as well in a few games.
"Some games we were physically dominant. It's a great achievement for this group and hopefully we can push on."
- Press Association