The British & Irish Lions have had chances to win both Tests, but came up short by five points in Durban and three in Pretoria. Now they have to win in Johannesburg to avoid becoming the first Lions team in history to be whitewashed in South Africa.
This is the 13th tour the Lions have undertaken to South Africa and only on four previous visits have they failed to win a Test. However, on each of those occasions - 1903, 1924, 1962 and 1968 - they managed to force at least one draw.
In 1938 and 1980, the Lions came into the final Test needing to win to avoid a whitewash and managed to conjure up famous victories. Ireland's Sammy Walker led the 1938 side to a 21-16 victory in Cape Town and England's Bill Beaumont skippered the 1980 tourists to a 17-13 triumph in Pretoria.
"The boys are really gutted we have lost the series, but we have earned some respect and there is still a huge amount at stake. If we don't front up and perform, then all the hard work and effort we have put in over the past five weeks could go down the tubes," said Gatland.
"We have got to finish this tour on a real high with a very solid performance. The tour will be a failure if we get whitewashed.
"We have got to win the game. If we get well beaten then you have nowhere to hide - we have worked too hard for that to happen.
"A lot of the players are taking a lot of confidence and self-belief out of this tour, but some difficult questions are going to be asked of our players today. Character wise, there is a lot going to be asked of the players."
For the 2009 captain, Paul O'Connell, the significance of victory would be even greater than merely avoiding a whitewash against the world champions in this series. This will be his sixth successive Lions Test, along with outside half Stephen Jones, and he has yet to taste success.
The Lions are also seeking to avoid their second a second successive whitewash - they went down 3-0 in New Zealand four years ago - and losing their eighth successive Test on tour in the southern hemisphere.