Twice-capped Tyler Morgan will start for Wales in Saturday's World Cup quarter-final against South Africa at Twickenham.
Morgan, 20, beat 80-cap James Hook to plug the gap created by Wales' midfield injury crisis. Gethin Jenkins returns for Paul James at loose-head prop and Dan Lydiate is recalled in the back row. George North returns to wing from centre and Justin Tipuric drops to the bench as Lydiate returns.
Lock Alun Wyn Jones will win his 100th Test cap - 93 for Wales to add to his six British and Irish Lions Tests.
North was at centre for Wales' 15-6 Pool A defeat by Australia. The recurrence of wing Liam Williams' foot injury in that game narrowed the selection options open to coach Warren Gatland. The New Zealander pondered fielding Hook in midfield alongside Jamie Roberts.
But Newport Gwent Dragon Morgan fills the gap created by injuries to Jonathan Davies, Cory Allen and Scott Williams.
Gatland said it was "not tough at all" to pick Morgan in such a big game. "Tyler had a bit of tight hamstring last week so he wasn't in contention [against Australia]," he added. "I think if you look at the squad we've been 100% consistent with the selections of the guys who were originally selected. "We thought Tyler played very well against Fiji for a young 20-year-old and we're putting that faith in him to back him again. He's an out and out 13 and he's definitely a player for the future and it's a great opportunity for him. "I can't see where the debate is about that selection." Ospreys' Lydiate returns after suffering an eye socket injury that required a plate to be inserted while Jenkins was rested against the Wallabies. Gatland said moving captain Sam Warburton to blind-side flanker against the Wallabies in Lydiate's absence was a "compromise". Lock Bradley Davies is on the bench after recovering from a broken nose, with prop Aaron Jarvis and back rower Ross Moriarty dropping out of the match squad.
Gatland said: "After coming through an incredibly tough pool, we are excited to be in the quarter-finals and returning to Twickenham.
"The physicality and intensity of the matches so far will stand us in good stead for what is going to be a huge battle against the Springboks. "They have grown game on game in this tournament and we know the challenge that faces us from a talented South African side." Wales won their last meeting with the Springboks, triumphing 12-6 at the Millennium Stadium in November, but had lost their previous 16 encounters. Wales team Backs: Gareth Anscombe (Cardiff Blues), Alex Cuthbert (Cardiff Blues), Tyler Morgan (Newport Gwent Dragons), Jamie Roberts (Harlequins), George North (Northampton Saints); Dan Biggar (Ospreys), Gareth Davies (Scarlets). Forwards: Gethin Jenkins (Cardiff Blues), Scott Baldwin (Ospreys), Samson Lee (Scarlets), Luke Charteris (Racing 92), Alun Wyn Jones (Ospreys), Dan Lydiate (Ospreys), Sam Warburton (Cardiff Blues, capt), Taulupe Faletau (Newport Gwent Dragons). Replacements: Ken Owens (Scarlets), Paul James (Ospreys), Tomas Francis (Exeter Chiefs), Bradley Davies (Wasps), Justin Tipuric (Ospreys), Lloyd Williams (Cardiff Blues), Rhys Priestland (Bath Rugby), James Hook (Gloucester Rugby).