The 17-year-old lightweight, who will meet Serik Yeleuov of Kazakhstan on Friday for a place in the final, has already secured at least a bronze to become the youngest Olympic medallist in his sport in over 50 years.
Britain's one-man boxing team, Khan had set his sights on the Beijing Games in 2008 until remarkable results this year won him a ticket to Greece.
"I'm only 17 and I had expected to go the next Olympics," he said. "Just being here is a great achievement. All the rest is a bonus."
With dazzling skills and maturity beyond his years, he soon exceeded expectations, cruising past his first opponent before teaching Bulgaria's European champion Dimitar Stilianov a boxing lesson and destroying South Korea's Baik Jong-sub to storm into the last four.
If he repeats the kind of form he has displayed so far, there is no way Yeleuov can stop him and already looming is a final clash with Cuba's Mario Kindelan, nearly twice Khan's age at 33 and widely regarded as the world's best pound-for-pound amateur boxer.
"The pressure is off me now and I think I will be more relaxed and could box even better in the next contests," Khan warned.
The youngest boxing medallist since Floyd Patterson in 1952, Khan has the potential to match the American and become a professional boxing champion.
IRRITATED COACH
One of the sport's all-time greats, Patterson went on to become a world champion in the professional ranks four years later, at just 21.
Such comparisons irritate British coach Terry Edwards, who is aware that Khan's amateur career is only just starting and is keen to protect his boxer from the growing hype.
"He's just come out of the juniors and already he is being bracketed in the same league as Muhammad Ali," said Edwards.
"Sometimes I'm aghast at what I hear and read. Amir has his feet on the ground and he will decide on his future when the time is right."
If he upsets Kindelan, Khan, the son of a Pakistani scrap metal merchant from Bolton in northern England, could be described as the greatest talent to step into the Olympic ring since Sugar Ray Leonard 28 years ago in Montreal.
He has not done yet by far here but even if he fails, lucrative offers for him to turn professional which he could find hard to resist will soon abound.
Khan insists he wants to carry on until Beijing but if he did not, the family could still be represented in China.
His younger brother, Haroon, is also a bright prospect and will be 17 then.
"A lot of people think Haroon will be better than me", Khan said.
