Savea, who has played five tests off the bench since making his debut against Wales in June, replaces the injured Sam Cane at openside flanker in a settled matchday squad of 23.
Flyhalf Lima Sopoaga has come onto the bench for Aaron Cruden in the only other change from the side who beat Argentina 57-22 in Hamilton last Saturday.
"We're really looking forward to Saturday's encounter, as South Africa is one of our traditional foes," All Blacks coach Steve Hansen said in a statement.
"We have built up a great relationship over the last few years and respect the South Africans immensely.
"We know they'll be hurting and desperate to get a result after their loss on the weekend."
Savea's first test start had been expected after impressive performances off the bench this season, though Hansen had hinted earlier this week that his elevation to the role was far from automatic.
Hansen had bought experienced Canterbury flanker Matt Todd, who has played three tests, into the side as cover for Cane, who injured his hamstring early in the second half against Argentina and was expected to be out for up to six weeks.
The All Blacks coach said at the time he liked Savea's explosive impact as a replacement and was still mulling over whether to give Todd the start and leave the 22-year-old to continue to develop his game from the bench.
Todd, instead will come off the bench on Saturday at Rugby League Park in Christchurch.
Cruden, who started the season as the first-choice flyhalf before being overtaken by Beauden Barrett, sustained a groin strain during training this week.
Team: 15-Ben Smith, 14-Israel Dagg, 13-Malakai Fekitoa, 12-Ryan Crotty, 11-Julian Savea, 10-Beauden Barrett, 9-Aaron Smith, 8-Kieran Read (captain), 7-Ardie Savea, 6-Jerome Kaino, 5-Sam Whitelock, 4-Brodie Retallick, 3-Owen Franks, 2-Dane Coles, 1-Joe Moody.
Replacements: 16-Codie Taylor, 17-Wyatt Crockett, 18-Charlie Faumuina, 19-Luke Romano, 20-Matt Todd, 21-TJ Perenara, 22-Lima Sopoaga, 23-Anton Lienert-Brown
(Reporting by Greg Stutchbury; Editing by Toby Davis)
