The South Africa Under-20 side produced a stunning second-half performance in Cape Town on Tuesday to beat England 28-15 and book a semifinal spot.
The Baby Boks ran in four quality tries in the second half to secure the vital bonus point in an intense match marked by the impressive level of physicality of both sides.
England had done well to keep the hosts at bay in the first half, and dominated South Africa in the set-pieces - stealing six of their line-outs and shoving them backwards at scrum-time.
South Africa battled to get any meaningful momentum going and could not breach the stout English defence before half-time, so it was the visitors who took a slender 3-0 lead into the break thanks to a long-range penalty from their fullback Tommy Bell.
However, things took a turn in the second half as South Africa came out and produced some accuracy to go along with the urgency that they had shown from the first whistle.
Outside centre William Small-Smith, who was standing in as captain for the injured Wiaan Liebenberg, got the first try when he broke the English defensive line thanks to a well-timed pass from his centre partner Jan Serfontein in midfield.
England hit back with another penalty from Bell, but the momentum was clearly with South Africa and their forward pack stormed back into the England 22 with a powerful drive that resulted in hard-working flank Shaun Adendorff crashing over for the try.
England only needed to win the game in order to qualify for the semifinals, and they drew closer thanks to two further penalties from the boot of Bell which reduced the deficit to 14-12.
However, South Africa were not done there and the next try came shortly afterwards when the imposing Pieter-Steph du Toit handed off an England tackler in the 22 to coast over.
Despite the fact that they were leading 21-12 it was not enough for South Africa who still needed one more try to secure the bonus point and their place in the semifinals, and as a result they showed plenty of desperation as they hammered away at the English defence.
The wall finally burst when wing Paul Jordaan made a break down the right to open up some space for Adendorff who put his head down and raced over for the crucial try which was converted by flyhalf Handre Pollard.
England tried desperatley to get within striking distance by kicking another penalty towards the end of the match, but they could not find a way through the South African defence and the Baby Boks held on for a famous victory which sets them up for a semifinal showdown with Argentina who beat Scotland 17-12 to maintain their unbeaten record in the tournament.
The other semifinal will be between defending champions New Zealand and the only team to ever beat them at the Junior World Chmpionships - Wales.
The Welsh followed up their gritty 9-6 victory over the Baby Blacks with a convincing 74-3 demolition of Samoa whilst in other matches on Tuesday Ireland beat Italy 41-12 and France beat Australia 31-7.
All the results and scorers from Tuesday:
Wales 74-3 Samoa - UWC Stadium
Tries: Allen, Harris, Walker, Jenkins, Thomas, Jones, Morgan, Jones, Pascoe, Prydie 2
Cons: Prydie 8
Pen: Ah Ki
Wales: 15 Ross Jones, 14 Tom Prydie, 13 Cory Allen, 12 Thomas Pascoe, 11 Eli Walker, 10 Matthew Morgan, 9 Tom Habberfield, 8 Dan Baker. 7 Daniel Thomas, 6 Luke Hamilton, 5 Matthew Screech, 4 Rhodri Hughes, 3 Samson Lee, 2 Kirby Myhill (captain), 1 Rob Evans.
Replacements: 16 Darran Harris, 17 Gareth Thomas, 18 WillGriff John, 19 Ieuan Jones, 20 Ellis Jenkins, 21 Jonathan Evans, 22 Sam Davies, 23 Jack Dixon.
Samoa: 15 Fomal Ah Ki, 14 Jason Tagiilina, 13 Peter Schuster, 12 Robert Lilomaiava, 11 Utu Poliko, 10 Zachary Schuster, 9 Vavao Afemai, 8 Airi Hunt, 7 Oneone Fa'afou, 6 Talaga Alofipo, 5 Tumama Tu'ulua, 4 Risati Faamatuainu, 3 Petelo Masei, 2 Ropeti Lafo (captain), 1 Alex Iosefa.
Replacements: 16 Damien Tovio, 17 Raymond Salu, 18 Andrew Broomhall, 19 Elekana Laupola, 20 Elia Togitele, 21 Faatafa Maiava, 22 Lomitusi Ulu, 23 Fale Iosefa
New Zealand 33-12 Fiji - UWC Stadium
For New Zealand:
Tries: Preston, penalty try, Emery 2, Proctor
Cons: West 4
Tries: Simolo, Sassen
New Zealand : 15 Matt Proctor, 14 Junior Tofa-Va'a, 13 Jason Emery, 12 Pita Ahki, 11 Milford Keresoma, 10 Ihaia West, 9 Jonathan Kitto, 8 Taniela Manu, 7 Jake Heenan, 6 Glen Preston, 5 Christian Lloyd, 4 Nick Ross, 3 Fraser Armstrong, 2 Rhys Marshall, 1 Tuki Raimona.
Replacements: 16 Nathan Harris, 17 Eric Sione, 18 Ofa Tuungafasi, 19 Hugh Blake, 20 Jordan Taufua, 21 Scott Eade, 22 Ope Peleseuma, 23 Ambrose Curtis.
Fiji: 15 Matayavusa Lea (captain), 14 Fred Hickes, 13 Sevanaia Galala, 12 Samu Kerevi, 11 Elia Ratucove, 10 Alifereti Mocelutu, 9 Seru Cavuilati, 8 Aca Simolo, 7 Meli Baivatu, 6 Ledua Ratumuri, 5 Joketani Raikabula, 4 Temo Raibevu, 3 Petero Tivitivi, 2 Jale Sassen, 1 Alex Hodgman
Replacements: 16 Etuati Qadroro, 17 Sunia Tamani, 18 Semi Keli, 19 Esikia Macu, 20 Sitiveni Nawaqa, 21 Sakiusa Gavidi, 22 Timoci Seruwalu, 23 Jimilai Rokoduru.
Ireland 41-12 Italy - Cape Town Stadium
Tries: Nelson 2, McGrath, Rael, Farrell, Conneely
Cons: Carty 4
Tries: Padovani, Calabrese
Ireland: 15 Mikey Sherlock, 14 Conor Finn, 13 Peter Nelson, 12 Chris Farrell, 11 Sam Coghlan-Murray, 10 Jack Carty, 9 Luke McGrath, 8 Jack Conan (captain), 7 Josh Van der Flier, 6 Aaron Conneely, 5 Iain Henderson, 4 Alan O'Connor, 3 Peter Reilly, 2 James Rael, 1 Des Merry.
Replacements: 16 Niall Scannell, 17 Tadhg Furlong, 18 Jake Cawley, 19 Tadgh Beirne, 20 Shane Buckley, 21 Kieran Marmion, 22 Cathal Marsh, 23 Stuart Olding.
Italy: 15 David Odiete, 14 Alex Morsellino, 13 Giovanni Benvenuti, 12 Andrea Bettin, 11 Filippo Guarducci, 10 Edoardo Padovani, 9 Guido Calabrese, 8 Vittorio Marazzi, 7 Zanini Guglielmo, 6 Ruben Riccioli, 5 Alfio Luca Mammana, 4 Marco Bellucci, 3 Leonardo Bortoletti, 2 Giovanni Scalvi, 1 Giovanni Maistri (captain).
Replacements: 16 Luca Conti, 17 Sami Panico, 18 Pietro Ceccarelli, 19 Alessio Zdrilich, 20 Federico Conforti, 21 Marcello Violi, 22 John Apperley, 23 Giulio Bisegni.
South Africa 28-15 England - Cape Town Stadium
For South Africa:
Tries: Adendorff 2, Du Toit, Small-Smith
Cons: Pollard 4
Pens: Bell 5
South Africa: 15 Dillyn Leyds, 14 Paul Jordaan, 13 William Small-Smith (captain), 12 Jan Serfontein, 11 Pat Howard, 10 Handrè Pollard, 9 Vian van der Watt, 8 Fabian Booysen, 7 Pieter Steph du Toit , 6 Shaun Adendorff, 5 Ruan Botha, 4 Paul Willemse, 3 Oliver Kebble, 2 Jason Thomas, 1 Steven Kitshoff.
Replacements: 16 Mark Pretorius, 17 Allan Dell, 18 Khaya Majola, 19 Braam Steyn, 20 Abrie Griesel, 21 Marais Schmidt, 22 Tshotsho Mbovane, 23 Maks van Dyk.
England: 15 Tommy Bell, 14 Marland Yarde, 13 Sam Hill, 12 Ryan Mills, 11 Charlie Walker, 10 Tom Heathcote, 9 Dan Robson, 8 Jack Clifford, 7 Chris Walker (captain), 6 Billy Vunipola, 5 George Merrick, 4 Sam Twomey, 3 Kyle Sinckler, 2 Koree Britton, 1 Luke Cowan-Dickie.
Replacements: 16 Nathan Morris, 17 Alec Hepburn, 18 Ross Harrison, 19 Dominic Barrow, 20 Ben Nutley, 21 Ben Spencer, 22 Josh Bassett, 23 Ben Ransom.
Argentina 17-12 Scotland - UWC Stadium
Tries: Ezcurra 2, Ramella
Tries: Marvin Bhatti, Eadie
Argentina: 15 Gonzalo Ruiz, 14 Ramiro Finco, 13 Juan Cappiello (captain), 12 Juan Ignacio Brex, 11 German Klubus, 10 Joaquin Paz, 9 Felipe Ezcurra, 8 Facundo Isa, 7 Leandro Ramella, 6 Joaqin Camacho, 5 Juan Cruz Guillemain, 4 Ladislao Uriburu, 3 Matias Diaz, 2 Santiago Iglesias, 1 Santiago Garcia Botta.
Replacements: 16 Matias Sambran, 17 German Lefort, 18 Mariano Sanchez, 19 Lautaro Casado, 20 Rodolfo Ambrosio, 21 Sebastian Poet, 22 Felipe Nougues, 23 Pablo Matera.
Scotland: 15 Sam Hidalgo-Clyne, 14 Jamie Farndale, 13 Keith Buchan, 12 Finn Russell, 11 Tom Steven, 10 Tomasso Allan, 9 Matthew James Torrance, 8 Mitch Eadie, 7 Alex Henderson, 6 Gary Graham, 5 Andrew Redmayne, 4 Stuart Smith, 3 Gavin Robertson, 2 Fergus Scott (captain), 1 Jamie Marvin Bhatti.
Replacements: 16 George Turner, 17 Alex Allan, 18 Robin Hislop, 19 Jamie Swanson, 20 Callum Reid, 21 Murray McConnell, 22 Harry Leonard, 23 Robbie Ferguson.
France 31-7 Australia - Cape Town Stadium
Tries: Fuster, Jedrasiak, Martin
Cons: Escande 3, Laranjeira
France: 15 Vincent Martin, 14 Bastien Fuster, 13 Gael Fickou, 12 Jonathan Danty, 11 Yohann Artru, 10 Enzo Selponi, 9 Eric Escande, 8 Karl Chateau (captain), 7 Julien Kazubek, 6 Kelian Galletier, 5 Pierre Gayraud, 4 Paul Jedrasiak, 3 Pascal Cotet,2 Jean Charles Fidinde, 1 Jefferson Poirot.
Replacements: 16 Raphael Carbou, 17 Florian Fresia, 18 Sebastien Taofifenua, 19 Andrew Chauveau, 20 Etienne Quiniou, 21 Thomas Laranjeira, 22 Darly Domvo, 23 Jonathan Laugel.
Australia: 15 Lewis Holland, 14 James Dargaville, 13 Chris Feauai-Sautia, 12 Apolosi Latunipulu, 11 Allan Faalavaau, 10 Kyle Godwin, 9 Nick Frisby, 8 Thomas Cusack, 7 Liam Gill (captain), 6 Sean McMahon, 5 Curtis Browning, 4 Jed Holloway, 3 Leslie Makin, 2 Hugh Roach, 1 Pettowa Paraka.
Replacements: 16 Silatolu Latu, 17 Oliver Hoskins, 18 Sam Jeffries, 19 Benn Melrose, 20 Matt Lucas, 21 Con Foley, 22 Ulupano Seuteni, 23 Allan Alaalatoa.