Bundee Aki wins his 50th Irish cap on Saturday when he lines up for the keenly-anticipated Rugby World Cup Pool B match between the Six Nations Grand Slam winners and defending champions South Africa.
The 33-year-old New Zealand-born centre has been in outstanding form in Ireland's first two games, scoring four tries and being named man of the match in the 59-16 victory over Tonga last Saturday.
Irish talisman Johnny Sexton will captain a side that shows just one change from the one that started against Tonga, with Jamison Gibson-Park returning at scrum-half.
Conor Murray, Sexton's long-time half-back partner, drops to the bench.
Alongside Murray on the bench will be Dan Sheehan, who has recovered from injury and replaces Rob Herring as the replacement hooker.
Farrell has not followed his opposite number Jacques Nienaber in naming a 7-1 bench in favour of the forwards to the backs.
The Ireland coach prefers a more balanced four forwards and three backs.
The Irish are on a run of 15 successive Test victories, which includes one against the Springboks last November.
Hugo Keenan; Mack Hansen, Garry Ringrose, Bundee Aki, James Lowe; Johnny Sexton (capt), Jamison Gibson-Park; Caelan Doris, Josh van der Flier, Peter O'Mahony; James Ryan, Tadhg Beirne; Tadhg Furlong, Ronan Kelleher, Andrew Porter
Replacements: Dan Sheehan, David Kilcoyne, Finlay Bealham, Iain Henderson, Ryan Baird, Conor Murray, Jack Crowley, Robbie Henshaw