Jason is an Ambassador for HSBC, the Lions' Principal Partner, and is heading up their ambitious community rugby outreach programme. The HSBC Rugby Festivals across the UK, Ireland and South Africa will involve 60,000 children and 3,000 coaches.
But the two men, who between them have amassed 62 Test tries in 102 international appearances, only had 400 to deal with at St John's College as the best 20 schools from a project that invlved 20 different Townships acros Soweto, Alexandra and Mamelodi played in the final of a TAG rugby competition.
There were mixed teams competing at U10 and U13 levels and all the children benefited from some expert coaching from the famous double act.
"It is great that guys like Bryan invest their time in the future growth of the sport in their country. When you see the kids' faces when Bryan turns up it is amazing - even I get excited when I see him," said Jason.
"TAG rugby is a great way of teaching rugby to kids. Bryan and I taught some basic skills, like hand eye co-ordination, ball handling and passing skills, and the response from the kids has been fantastic
"The children were given a great opportunity and hopefully they can now go on to continue playing rugby and enjoying the sport."
For Bryan, and it was a day out in his home city the day after he had been announced in the 28 strong Springbok squad to take on the British & Irish Lions later this month. His appearance also came three days after he had helped the Bulls win the Super 14 title.
The reaction to him from the children was understandably enthusiastic, and his response to them was the same.
"It was great to see so many enthusiastic children enjoying the sport that I love so much. It was a privilege to join Jason at the event," said Bryan.
"He was one of my idols who I looked up to when I was younger. His moral values on and off the field are very special.
"Not many achieve what he has achieved and I would like to thank him for being such a great role model back in the UK and around the world. It is a real pleasure for me to be involved in the HSBC programme with him.
"I really hope that this TAG rugby programme will go on to produce a future Springbok or Blue Bull. I'd love to see someone from this programme go on to play rugby at the highest level.
"But hopefully all the kids involved will go back home and spread the word that rugby is fun. Both Jason and I told them the most important thing is to enjoy playing the game.
"It was a brilliant day for me and I'm grateful to HSBC for getting me involved. Rugby is the best game in the world and the children were very fortunate to be able to learn from Jason Robinson - one of the greatest players in the world.
"I've also been involved with the SOS IRB Kit Aid scheme that HSBC has backed. It was very special for me to meet children at Pimlico Academy in London last year who so generously donated their rugby kit.
"To see the response from the kids here in South Africa is just unbelievable."