Grieve's 40-yard kick helped the Lions secure a 21-16 victory and avoid a series whitewash in the last Lions tour for 12 years.
The kick itself could easily have not been awarded by the referee who had a poor view of the posts, but a number of South African players signalled that the kick was good, meaning the four points stood.
Having previously represented his country as a fly-half, Grieve appeared just once in a Lions shirt during the first 15 games on tour. When he did finally earn a fair chance in the starting XV, playing full back in place of the injured Viv Jenkins, Grieve made such an impression that he played in eight of the remaining nine fixtures, including the second and third Tests.
The outbreak of the Second World War ensured the 1938 tour would be Grieve's only chance to wear a Lion shirt, while his international career with Scotland lasted just two appearances.
Grieve died in Ludlow, Shropshire in June 2000.
Charles Grieve's factfile
Date of birth: October 1 1913
Club: London Scottish
International caps: Scotland 2
Grieve's Lions lowdown
Lions debut: Versus Western Province (Town and Country), June 18, 1938
Lions Tests: 2 (2nd and 3rd Tests vs SA in 1938)
Lions non-Test appearances: 6
Total Lions appearances: 8 (all in 1938)
Lions points: 7* (two conversions and a drop goal) *under the current scoring system of two points for a conversion and three for a drop, although Grieve's drop was worth four points at the time
Final Lions appearance: Versus Western Province (Country) September 21, 1938
That famous drop
Having already lost the first two Tests of the three-match series, the Lions found themselves trailing 16-14 with just five minutes remaining of the final Test at Newlands.
Retiring Springbok coach Danie Craven appeared to be about to receive the perfect send off in his last game in charge, but Grieve had other ideas.
Gathering a South African clearance kick just a metre in from touch, Grieve launched a stunning drop goal towards the uprights, seemingly without breaking stride.
The kick was successful and the Lions moved into an 18-16 lead to put them on the cusp of victory.
A late try sealed the win for the tourists who had showed typical Lions character to overturn a 10-3 defecit.
Fittingly, Grieve was named man-of-the-match in his final Test appearance as a Lion.
Grieve and other sports
As well as achieving the ultimate selection as a rugby player, Grieve was also a fine cricketer. A right-handed batsmen, he played first-class cricket for Oxford University, albeit on just the one occasion. He also played cricket for the Authentics (Oxford's Second XI), for Hampshire Seconds and for I Zingari and earned a Blue at golf, winning his singles match 6 & 5.
Golf had been a lengthy passion of Grieve's thanks in no small part to the fact that he had spent many of his school holidays staying with an aunt in St Andrews. By the age of 16 he was recording scores of 75 on the Old Course, and driving the Swilcan Burn from the first tee. In 1931, he was a member of the Scottish Boys' golf team which beat England at Killermont in Glasgow.
During his time in the Army, Grieve was posted to Gibraltar where he was voted the colony's Sportsman of the Year and won the Southern Spain Golf Championship by 12 strokes. He became Army golf champion and even at the age of 80 went round a course in 78.
An eventful debut
Grieve made his Scotland debut against Wales in 1935 but his celebrations were shortlived after he suffered a nasty injury. The debutant was severely concussed during the match and it was feared that he would never play again. However, fortunately for Grieve himself and for the Lions, he returned to action after nine months on the sidelines.
The War and what came after
Grieve served in France, Abyssinia and the Far East during World War Two. He then continued his Army career with the Duke of Wellington's Regiment, fighting in Korea and eventually rising to the rank of Major.