The 18 year-old ended the tour as Barca's top scorer and created such a clamour from Japanese and Chinese media that there was pressure on coach Frank Rijkaard to continue selecting him. Demand for Dos Santos interviews outstripped requests for big-names Thierry Henry and Ronaldinho and now after only a few days on the other side of the world, Barca's marketing team know they have the world's next big thing on their books.
And it will be Dos Santos' year. The attacking midfielder will collect his Spanish passport before the end of the month and the form he showed last week will give Rijkaard a welcome headache. Never mind how he fits his 'Big Four' into the team - how will he handle the growing pressure to give a young Mexican his chance?
For all his unpredictable flair and flamboyance, Dos Santos has emerged from a very organised and systematic career path. His Brazilian father, Zizinho, a former star with Sao Paulo before enjoying further success in Mexico with Monterrey and America, brought on Giovani's talent through his own football school. Zizinho established the Sao Paulo soccer school in Monterrey, where Giovani was the star pupil. His son's first taste of success was in the prestigious Dallas Cup youth tournament, where Sao Paulo won the U12 division and Giovani won the plaudits. That success convinced Zizinho his son needed exposure to a professional environment and he was soon signed to Monterrey.
"My Dad is a very important person, he was my first coach, he taught me how to play and I have footballer's blood thanks to him," says Giovani. "But both (Mum and Dad) have supported me since we changed countries. I am grateful to them for everything."
Only weeks into his time at Monterrey, a last-minute call to join a tour of France by their youth squad was to change Giovani's life forever.
Monterrey faced a Sevillan team with Barcelona ties during the trip and Dos Santos' performance was enough for their coach, German Vaya, to immediately call Barca's youth chief at the time, Joaquin Rife, and alert him to this prodigious talent. Soon Barca president Joan Gaspart and sports director Carles Rexach were on the phone to Zizinho to close a deal for the 13 year-old.
That one-off game in France not only changed the life of Giovani, but also younger brother Jonathan. Now 17, Jonathan has been with Giovani at Barca since his early teens and such has been his progress that he is expected to feature for Pep Guardiola's Barcelona B this season. Zizinho's eldest son, Eder, is also a pro, having just signed with Club America's satellite team, Socio Aguila.
"I am very happy seeing my children have success," says Zizinho. On Giovani's development, he is adamant: "The skill of walking, running, mainly dribbling with the ball that Giovani possesses is typical of a Brazilian player. I'm very happy about this."
Giovani could easily have declared for Brazil before leading Mexico to the U17 World Championships crown two years ago. As Zinedine Zidane now hints, you fancy Brazilian fans will long be lamenting Zizinho's reluctance to push his son to choose Brazil over the nation of his birth.
"He is a very good player," says Zizou. "I enjoy watching him play. He's something different, with great vision, and it's good he's playing for Mexico. Barcelona must take care of him and protect him."
Zidane needn't worry. As they did with Lionel Messi, Barca have placed a protective shield around Dos Santos - both on and off the pitch. A Mexican TV crew's request to profile the teen was knocked back before he left for the Far East and his media appearances in Japan and China - while standing room only - were carefully stage-managed.
On the playing side, Barca's fitness staff won't get near the 18 year-old with a weights program for another two years. He's currently regarded as being two kilos overweight, but that's of no concern given his age. However, Giovani's diet will change this year as he can stack on the kilos easily.
Also like Messi, Dos Santos has been taken under the wing of Ronaldinho. The Brazilian ace is regarded as the one senior player closest to Dos Santos. Tales of pranks in hotel rooms and delaying flights involving the pair only added to Dos Santos' popularity amongst the Asian media.
But for all the high spirits, Barca's senior players are sure to keep him grounded. Fellow Mexican Rafael Marquez explained: "He knows he must keep his feet on the ground and work hard. He knows how competitive things are here at Barca.
"I think we all know about the potential that he has and we will help him in anyway possible to maintain his improvement."
Just like those few days in France five years ago, a week on the other side of the world has marked another leap forward in Giovani Dos Santos' career.