He then kept the flame alive in their 2-1 defeat of Qatar and Round of 16 success against Ukraine, before blazing with even more intensity in the quarter-finals, scoring the only goal to see off Uzbekistan 1-0.
The heat now looks set to rise with Brazil next up in the last four, but – away from the pitch at least – Thiam remains ice cool. "We're happy to be where we are," he explained to FIFA.com. "We've done the job we had to do and let's not take away from that, but honestly I don't look at what we've done as a big deal.
Although Les Lionceaux (Lion cubs) may be concentrating on the future, it is harder to picture any team enjoying a more perfect baptism of fire thus far. No debutants have reached the U-20 World Cup semi-finals since Ghana in 1993, but Thiam is not surprised at all by his side's achievements.
"When you look at it, Senegal have only ever been to one senior World Cup and they reached the quarter-finals. We're made to do well in big competitions. It's true that we can take our time qualifying, but once we get through we don't do things by half measures."
Senegal proved that beyond doubt when they made their FIFA World Cup™ bow at Korea/Japan 2002, reducing the hopes of defending champions France to ashes in a 1-0 win. The result sent shockwaves around the world and not least in France itself, where Thiam was born and raised.
It was there too that he progressed from amateur football to the professional game, spending time at Red Star and Drancy before joining current club Dijon. "But my country is Senegal," he said. "That's where my roots are. In fact, I go there as much as I can, any time I get some spare time."
Not only does the No19 have his roots in Senegal, he boasts national team DNA as well, with his father Pape Idrissa Thiam having turned out for the Lions of Teranga as a player and his grandfather Abdoulaye Thiam having coached the side in 1963.
"We have football in our blood," said the youngest of the trio. "Actually, they were the first people I thought of, as well as my other grandfather, who's a sports journalist, when the final whistle blew at the end of our match with Uzbekistan."
Despite that lineage, Thiam's father did not want him to follow in his footsteps, and took a long time before letting his son pursuing a career in the game. "He was absolutely determined that I should study until I was 18," said Thiam. "I'm aware that you mustn't take education lightly, but I've only ever thought about football.
"I just couldn't help it. And he couldn't get in the way of that passion. As a result, I don't have any other option than to succeed. It's out of the question for me to disappoint him. But I think he's proud of me. In any case, he never misses a game."
At the moment, how could he? Thiam has been in superb form since the U-20 World Cup began, making a nuisance of himself across the forward line to help Senegal advance. His goal against Los Cafeteros was particularly impressive, Thiam losing his marker and dribbling past a pair of defenders before firing a calmly taken shot low into the corner.
And while his playing talents have grabbed a lot of attention, his bright orange hairstyle has caught the eye almost as much. "It's a bit of a nod to Gouye Gui, a very good friend of mine who's a wrestler and big star back home," he said. "He likes to dye his hair and I decided to do the same thing."
Of course, when Thiam decides on a course of action, nothing in the world can stop him – as his father would no doubt confirm. So, when the young forward insists he will settle for nothing less than the title in New Zealand, the rest of us should probably believe him. After all, anything else would be playing with fire.