Unlike some of the celebrity ice dancers in the ITV show which preceded his appearance, the Olympic lightweight silver medallist did not put a foot wrong. A perfect six this time, even if it only went less than one: 72 seconds, to be precise.
By coincidence the bout took place in the city where Jayne Torvill and Christopher Dean launched their own dancing years at the forerunner to this new ice rink venue. Like the tangoing twosome, young Khan has a natural instinct for knowing when to put the skates on.
The Belorussian presented an upright stance, but not for long, succumbing to Khan's blurring rat-tat attack which culminated with a clipping right bang on the button. He went down, regained his feet but was sufficiently dazed for the referee, Terry O'Connor, to step in.
Martynov, 22, Khan's first foreign foe, came with a tidy record of 10 wins in his 11 pro fights, albeit having been stopped in two rounds in Germany by Frenchman Willy Blain when he ventured outside his homeland for the first time two months ago. The tall man from Minsk clearly is not a good traveller.
Buoyed by the FA Cup victory of his hometown team Bolton over Arsenal, the 19-year-old Khan delivered his own knock-out blow watched by a sell-out crowd of 8,000, almost as many as at the Reebok. "Two winners from Bolton," Khan quipped.
Naturally he was as pleased as his punch, but did admit it was somewhat unsatisfactory. He had hoped to experience a longer test. "I was a bit upset in view of all the training I had to do for my first six-rounder." But as he said: "I went in there and did my job. You don't get paid for overtime."
Next is a date on the Danny Williams-Matt Skelton heavyweight bill at London's Excel Arena on 25 March, and hopefully a further step up in the class and durability of opponent.
"He still has a lot of work to do," says former world champion Duke McKenzie, "but this boy is the future of boxing. He can do anything he wants in the sport if he develops and that includes being a world champion at a similar age to Naseem Hamed."
Khan, who enjoys a bit of showboating, says he has no wish to become a Naz clone, branding the ex-world featherweight champion as "arrogant and cocky". That's not Khan's style, although his fight was followed on the ITV screens last night by a documentary on the life of his idol, Muhammad Ali. If he wants to follow a star, there is none brighter in the fistic firmament.
"I'm going to get better and better," Khan vowed. You had better believe him. The Amir effect is stunning, as Martynov soon discovered.
In what was billed as the main event, the West Bromwich battler who fights under the quaint nom de guerre of Young Muttley - real name Lee Woodley - snatched the British welterweight title from the previously unbeaten Lancastrian holder, Michael Jennings, edging a split decision over 12 rounds.
Yet to many ringside observers, the more skilful Jennings seemed to have done enough to keep the crown despite a stirring finish by the challenger.
Jennings is himself known in the trade as "The Lurcher" and with 29-year-old Muttley, named after the Seventies cartoon hound, it had the makings of a spectacular dogfight.
Instead it turned out to be a rather gruelling, scrappy affair. Muttley, who claims boxing put him on the straight and narrow after a spell in jail for assault eight years ago, landed some hurtful blows but Jennings threw a far greater volume of punches.
However, this failed to convince two of the judges, who made the aggressor Muttley the winner by three rounds, the third giving it to Jennings by two.