Neymar scored in the 71st minute at the Camp Nou on Tuesday to clinch a 1-1 draw for Barcelona in their UEFA Champions League quarter-final first leg against Atletico.
The Brazilian burst in from the left wing to collect a pin-point pass from Andres Iniesta and then slotted the ball inside the far post to cancel out Diego's opener for the visitors.
Since Neymar signed with Barcelona, there have been claims the Brazilian attacker is not worth what the club paid for him, with former coach Johan Cruyff among the critics.
But Martino argued Neymar's goal was a big statement for the 21-year-old, who is also still recovering from an ankle injury that sidelined him in February.
"Obviously, for any player in his situation, where he was trying to recover his level working really hard, this (the goal) is a really important moment," Martino said in his post-match press conference.
"And apart from this, he made a great match, and of course, this goal helps us, but especially him."
Tuesday's game was the fourth consecutive draw between Atleti and Barca this season.
The match was a tense affair in the first half with few genuine goal-scoring opportunities but opened up after the break, with Diego producing a scorching strike into the top corner to give the visitors the lead in the 56th minute.
While the draw should make Atleti slight favourites to advance to the Champions League semi-finals, Martino was pleased with Barcelona's performance.
"It's a match where we tried more and got better. It's a match where we had more chances to win. I think that we kept the intensity during the 90 minutes and where we tried to win playing as Barcelona does," the Argentine coach said.
One negative for Barcelona was that Gerard Pique was subbed off in the 12th minute for Marc Bartra after an awkward fall.
"(Pique) asked to be subbed off after he noticed pain in his hip due to a pelvic contusion," a statement on Barcelona's website read.
"Marc Bartra came on in his stead. (Pique) will undergo additional tests to determine the extent of the injury."
