Ulsterman Walker was one of five players from his province in the side and there were a record eight Irishmen in the team. It was the first Lions Test win in South Africa in 28 years and ended a run of seven games without a victory.
The Springboks were 13-3 ahead at the break and seemingly on route to another 3-0 series whitewash. But Walker's men scored 18 second half points to rock their hosts and restore some pride.
The victory ended a run of six successive Test defeats by the Lions and was the most points scored by the Lions in a test in South Africa - a record that stood until 1974.
Walker's men scored four tries. Can Paul O'Connell's side, with seven Irishmen on board, do the same today.
DATELINE: 10 September, 1938
VENUE: Newlands, Cape Town
South Africa 16 British Lions 21
HT: 13-3 Attendance: 18,000
South Africa: G Smith; D Williams, P de Wet, F Turner, J Bester; T Harris, D Craven [capt]; F Louw, J Lotz, B Louw, R Sherriff, B du Toit, F Bergh, L Strachan, E Bastard
Scorers: Try - F Turner, J Lotz, J Bester; Conversion - F Turner (2) ; Penalty - F Turner
British & Irish Lions: Charles Grieve (Oxford Uni / Scoltland); Elvet Jones (Llanelli), Jimmy Giles (Coventry / England), Harry McKibbin (Queen's Uni, Belfast / Ireland), Veysey Boyle (Dublin Uni / Ireland); George Cromey (Queen's Uni, Belfast / Ireland), George Morgan (Clontarf / Ireland); Bob Graves (Wanderers / Ireland), Bunner Travers (Newport / Ireland), Gerry Dancer (Bedford), Sam Walker (Instonians / Ireland, captain), Blair Mayne (Queen's Uni, Belfast / Ireland), Laurie Duff (Glasgow Academicals / Scotland), Jack Waters (Selkirk / Scotland), Rob Alexander (NIFC / Ireland)
Scorers: Tries: L Duff, E Jones, R Alexander, G Dancer; Con: H McKibbin; Pen: H McKibbin; DG: C Grieve
Referee: Nick Pretorius (South Africa)