Yafai was still working full-time at the Land Rover factory in Solihull when his older brother Kal controversially missed out on a place in the boxing squad for London 2012.
Nine years later the 28-year-old ended any lingering sense of Olympic injustice by dropping and defeating Paalam by a split decision - one of the five judges scored in favour of the Filipino.
While Kal went on to claim a professional world crown and another brother, Gamal, won a European title, Galal admitted he always struggled to believe those who persistently told him he was capable of achieving a similar level of boxing success.
But from the moment Yafai crumbled his opponent with a straight left in the opening round the result scarcely seemed in doubt. Yafai capped a series of stellar performances that have assured him, at least temporarily, of the family bragging rights.
"I'd have laughed at them," said Yafai when asked how he would have responded had he been told of the odyssey to come when he was working long hours at the car factory.
"All the coaches would tell me: 'Galal, you're going to be an Olympic champion', and I'd say: 'No chance.' I thought they were saying it to be nice to me, because they were my coaches. It sounds crazy to say I'm Olympic champion now.
"Whenever I do anything good it impacts on my brothers. So if I'm Olympic champion it's great for them. And when Kal and Gamal do well, it looks great on me as well. We're a close-knit family and we will celebrate together."
Yafai had made his Olympic debut in Rio when he lost to Cuba's eventual bronze medallist Joahnys Argilagos in his second fight.
A subsequent European silver medal in Kharkiv in 2017 gave the first glimpse of Yafai's true potential, and he was one of two British boxers, alongside Peter McGrail, who booked his place in Tokyo prior to the suspension of the qualifying process in March 2020.
Yafai, who spent much of the one-year delay confined to his Birmingham flat, came into his own in Tokyo, negotiating a tough route to the gold medal match, starting with a convincing stoppage win over Koryun Soghomonyan of Armenia in his preliminary bout.
A tight win over the crude Zambian Patrick Chinyemba provided a timely opportunity to refocus, and Yafai reaped the benefit in his following bout when he beat Cuba's former world champion Yosbany Veitia.
A medal duly guaranteed, Yafai went one better with a thrilling performance in his semi-final against Kazakhstan's Saken Bibossinov.
In Paalam, however, he faced an opponent with arguably an even more impressive path than his own, including a split decision win over Ireland's Brendan Irvine, plus a split decision victory over reigning Olympic champion Shakhobidin Zoirov in a quarter-final bout that was abridged due to injuries.
Paalam's is an extraordinary story in itself, a former scavenger on the rubbish tips of the Filipino capital Manila, who was persuaded to enter his first boxing bout at the age of seven and used the money to buy rice for his family.
Yafai won a high-octane first round largely due to a hard straight left that he landed midway through the round that dumped Paalam temporarily to the canvas.
The Filipino rallied but Yafai's greater precision also shaded the second round, despite catching a few of Paalam's crude right hooks, and although his opponent won the last round by shutout, it was not enough to wrest the gold away from Yafai.
Yafai will now be expected to follow his brothers into the professional ranks, and with a gold medal around his neck his marketable potential has certainly increased.
But he said he will take time to consider his future, and instead turned his attention to more pressing concerns.
"Obviously everyone wants to turn pro and I've been an amateur for a long time," said Yafai. "I've been to two Olympics but I'm going to have a rest with family and friends, and soak it all in.
"I don't want to think about boxing any more. I want to rest and I just want to eat some food. Maybe a nice Five Guys - a few chips, burgers, nothing healthy."