It was the Bulgaria winger's early goal in that opening game against Streymur in the Faroe Islands that set Mark Hughes' Blues on the long journey to our first European quarter-final in 30 years against UEFA Cup rivals Hamburg.
Petrov has been forced to sit out most of the season after damaging knee ligaments in a World Cup qualifier in October, but now he is desperate to bounce back into the fray to reinforce City's bid for glory.
The Premier League trip to Arsenal on Saturday has come just a little too soon for Martin, who like compatriot Valeri Bojinov will need a couple of run-outs to shake off the rust after five months, but he can certainly hear Germany calling.
Blues boss Hughes, confirming that Petrov is back in training, said: "He's on track now. There was a bit of concern a couple of weeks ago about the knee but ther specialist found it was just the stitching inside the knee.
"Maybe it was irritating the ligament. But he had an injection popped into it and that cleared it up. Now it's just a case of getting games into him. He's a fit guy and not the type to put too much weight on. Hopefully he'll be an option very soon."
Like team-mates Bojinov, Benjani and Danny Sturridge, Petrov is coming back into contention at just the right time to give manager Hughes a great boost for the Premier League finale as well our shot at Europe. Midfielder Michael Johnson can also see light at the end of the tunnel with his return.
City face a tough Premier League run-in as Hughes chases seventh place, while if Hamburg are overcome, either Werder Bremen or Serie A Udinese will stand between the Blues and that dream UEFA Cup final date in Istanbul on May 20.
So an injection of refreshed talent is just what the doctor ordered for Hughes and his Carrington staff. City's manager said: "You can introduce that energy and enthusiasm those players will have on their return.
"Sometimes in a long, hard season there's a dip, and you'll see that in certain players. If you've got the option just to take them out of the firing line, that's great to have. We've got players who are itching to get back into the side and that's going to be a real boost."