After sliding home a left-footed finish, the Lion Cubs midfielder ripped off his shirt and sprinted towards the home fans at Dakar's Leopold Sedar Senghor stadium, while the crowd erupted with joy. Reliving this moment in conversation with FIFA.com almost three months on was enough to coax Sarr out of his shell again: "It was a goal that we needed, plain and simple," he said, smiling.
This is no exaggeration. The hosts had been trailing 3-2 as late as the 88th minute until their No8 equalised with a powerful right-footed strike. Three minutes later up popped Sarr once again, this time with his other boot, to clinch Senegal's maiden win at the tournament and book their place at their first-ever FIFA U-20 World Cup.
The starlet's modesty is commendable, but there is no doubt that he was Senegal's key man throughout the event. Besides the aforementioned brace, he scored in their 3-1 loss to Nigeria in their opening game, provided two assists and was hugely influential in their all-round play.
Not for nothing was he handed the armband by coach Joseph Koto after that dramatic Congo DR encounter and subsequently named in the CAF team of the tournament. "These sorts of things are a pleasure. I'm really proud," replied this massive admirer of Yaya Toure when asked about this recognition, albeit not without a touch of embarrassment.
From Mbour to New Zealand
It is fair to say that few people were prepared for Sarr's explosion onto the scene. On the books at minnows Mbour Petite Cote, whom he joined in 2015 from no less modest Senegalese second-division outfit Dakar Sacre Coeur, he does not fit the mould of your typical national saviour. On top of this, he is younger than many of his team-mates (he will celebrate his 19th birthday during the group stage) and less experienced than the squad's Europe-based contingent, which is headed by Dijon's Mouhameth Sane, Monaco's Seydou Sy and Zaragoza's Alassane Sow.
And yet it was this shrinking violet off the pitch who rose to the occasion on it to lead his side to the promised land. Just do not ask him to describe this land in detail: "I don't know anything about New Zealand. All I know is that it's far away," he joked.
One figure who did, however, see the midfielder's emergence coming was Ibrahima Wadji, Sarr's team-mate and 'big brother' at club and international level. "I'm thrilled for Sidy, he thoroughly deserves it," the winger raved to the local media following his protégé's heroics on home soil. Fittingly, Wadji kept Sarr company in the team of the tournament too, having also netted three times.
The Mbour Petite Cote president, Mbaye Diouf Dia, is pleased to see the two youngsters flying the flag, even though the club is flirting dangerously with relegation. "It's true that the team's quality won't be the same as when they were around, but good for them," he stated, before adding: "Above all we are hoping for Senegalese football to make a big impression in this competition."
Sarr's response when FIFA.com put this to him was characteristically laconic: "We'll do our best." We have every reason to take him at his word.