Georgian halfback Vasil Lobzhanidze was four years old when Victor Matfield made his international debut, and now the duo are heading to the Rugby World Cup as the youngest and oldest players participating.
Matfield - aged 38 - is off to his fourth World Cup, and will be the elder statesman at the tournament. With most of the other over 35 players being on minnow squads with less competition for spots, Matfield's continued selection is noteworthy as the Springboks look for their third cup triumph.
Other old heads heading for another World Cup appearance include two Tongan players with links to New Zealand - 37-year old former Chiefs hooker Aleki Lutui and 36-year old former Highlanders forward Hale T-Pole.
All Blacks hooker Keven Mealamu will be the sixth oldest player at the tournament, at 36 years of age.
The oldest player to ever participate at a World Cup is Uruguay's Diego Ormaechea, who was 40 years old when he took on South Africa in 1999.
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Read more: Rugby World Cup by the numbers: Which squad is oldest?
On the other hand, Lobzhanidze is set to become the youngest ever player to play at a Rugby World Cup, being remarkably just 18 years of age. He will break the record of the USA's Thretton Palamo as the youngest player in World Cup history should he make an appearance in the pool stage.
Lobzhanidze, who impressively already has six caps, is the only teenager at the tournament, with eight players aged 20, including Wales winger Hallam Amos and Argentine lock Guido Petti Pagadizábal.
The youngest All Black is 23-year old Malakai Fekitoa, while Australia (Sean McMahon), South Africa (Jesse Kriel and Handre Pollard), France (Gaël Fickou) and England (Anthony Watson) will all call upon 21-year olds in their squad.
1. Victor Matfield (South Africa) 11 May 1977 (aged 38)
2. Hitoshi Ono (Japan) 6 May 1978 (aged 37)
3. Matekitonga Moeakiola (United States) 16 May 1978 (aged 37)
4. Aleki Lutui (Tonga) 1 July 1978 (aged 37)
5. Jamie Cudmore (Canada) 6 September 1978 (aged 37)
6. Keven Mealamu (New Zealand) 20 March 1979 (aged 36)
7. Hale T-Pole (Tonga) 30 April 1979 (aged 36)
8. Mauro Bergamasco (Italy) 1 May 1979 (aged 36)
9. Paul O'Connell (Ireland) 20 October 1979 (aged 35)
10. Mike Ross (Ireland) 21 December 1979 (aged 35)
1. Vasil Lobzhanidze (Georgia) 14 October 1996 (aged 18)
2. Damian Stevens (Namibia) 2 June 1995 (aged 20)
3. Sabin Stratila (Romania) 27 March 1995 (aged 20)
4. Louis van der Westhuizen (Namibia) 25 February 1995 (aged 20)
5. Titi Lamositele (United States) 11 February 1995 (aged 20)
6. Guido Petti Pagadizábal (Argentina) 17 November 1994 (aged 20)
7. Wian Conradie (Namibia) 14 October 1994 (aged 20)
8. Hallam Amos (Wales) 24 September 1994 (aged 20)
9. Janco Venter (Namibia) 19 September 1994 (aged 20)
10. German Kessler (Uruguay) 1 July 1994 (aged 21)