Beaten in the first two Tests in South Africa, they rung the changes for the third and final game in Cape Town and came up with one of the greatest Lions victories of all-time. Their 21-16 win sent the tour party home in good mood and it was a famous day for the Irish.
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)