In-form centre Bundee Aki believes his bulked-up frame has helped him make a storming start to the Rugby World Cup as he prepares to win his 50th Ireland cap.

New Zealand-born Aki tops the try-scoring charts in France with four, following back-to-back doubles in crushing bonus-point wins over Romania and Tonga.

The 33-year-old's first World Cup campaign, in 2019, ended prematurely with the ignominy of a first-half red card against Samoa in Fukuoka.

Fast-forward four years and Aki feels he is in far better physical shape ahead of a milestone Test appearance in Saturday evening’s momentous Pool B clash with reigning champions South Africa.

"The S and C (strength and conditioning) crew put together a great programme for us in pre-season," said the Connacht player.

"It’s a big difference from 2019, the way I was. I think Faz (head coach Andy Farrell) told me straight away not to go back to (being) that skinny. (I’m) not going back there.

"I’m just quite lucky to get on the end of those tries and some of the boys, the way they set up the ball for us, makes our jobs a lot easier."

Aki’s international debut came against South Africa – a 38-3 Dublin win in November 2017.

A repeat of that emphatic four-try triumph this weekend in Paris would propel Ireland into the quarter-finals with a fixture to spare.

Bundee Aki and Garry Ringrose will start together in the centre this week

"It’s a huge occasion," said Aki.

"But I’ll try not to treat it as a big occasion, just try to treat it as a game and do the things I do every week.

"Obviously, we’re going up against the world champions. For myself and my family, it’s a huge honour to be able to pull on the jersey 50 times.

"Every time you pull on that jersey, you try to play as best you can and put your best foot forward."

Garry Ringrose, who paid a touching tribute to midfield partner Aki, is braced for a "concoction of everything" from the Springboks.

"They pride themselves on their defence and they’re a really well-organised defensive team," said the Leinster man.

"Maybe from the outside it looks chaotic but you can see they’re all on the same page.

"They have players who can make a massive impact defensively, so that will put our attack under huge stress no doubt.

"Attack-wise, they have some of the most dangerous individuals in world rugby on top, top form, so when we don’t have the ball, there’s no room for switching off concentration-wise or we will concede.

"That’s not even to mention the physical challenge, so it’s a concoction of everything really."

Speaking of Aki, the 28-year-old said: "I consider myself lucky to play alongside Bundee and I think everyone in the group is unbelievably happy to see him get to 50.

"When he first came to Connacht he kind of captured everyone’s hearts there and he’s done that from the moment he put on the Irish jersey.

"It couldn’t be more deserved."

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