The 19-year-old right-hander retired the first 10 batters he faced and struck out six over four hitless innings as the Quad Cities River Bandits blanked the Wisconsin Timber Rattlers, 1-0.
"It all came out like I had dreamed it would," Martinez said through a translator. "After the first inning, it was just, 'Wow.'
"I don't want to say I was nervous, but I was just trying to feel myself. It was very emotional."
A native of the Dominican Republic, Martinez was perfect for the Cardinals' Class A affiliate the first time through the order, fanning two batters in each of the opening three frames.
T.J. Mittelstaedt drew a one-out walk in the fourth to give the Timber Rattlers their first baserunner, but Martinez got Cody Hawn and Michael Walker to fly out to keep the game scoreless.
The 6-foot flamethrower threw 30 of 52 pitches for strikes before turning things over to the River Bandits bullpen.
"I still want to get better with my command, especially on my fastball," Martinez said. "I want to work really hard."
River Bandits manager Johnny Rodriguez said the non-drafted free agent already has the makeup to be a star.
"I've been in baseball more than 30 years and he could be a No. 1 guy in St. Louis," Rodriguez said. "He was better than I had expected.
"He reminds me of when I saw a young Pedro Martinez in Albuquerque in the early '90s. In fact, he shows me more than what Pedro did at his age, and you know how his career went."
The Cardinals signed Martinez last April and he promptly led the Rookie-level Dominican Summer League with a 0.76 ERA in 12 starts. He went 3-2 with 78 strikeouts over 59 innings.
Martinez, who reportedly received a $1.5 million signing bonus, impressed the Cardinals' front office during a mini-camp bullpen session in Jupiter, Fla., prior to the start of Spring Training in February.
The velocity and life of his fastball drew a lot of attention, but Rodriguez was equally impressed with his off-speed pitches Saturday.
"His fastball was thrown at 97 to 99 mph and it exploded off the plate, but his curveball fell right off the table," he said. "That was what was so impressive, the spin on his breaking ball and the action on his changeup.
"In the last four or five years, his curveball was the best I have seen from such a young arm. They had five or six left-handed hitters in their lineup and still had no chance of hitting him. His mound presence was off the charts and his command was perfect."
Southpaw Kevin Siegrist (4-1) tossed five shutout innings in relief of Martinez, losing the no-hit bid with two outs in the seventh when Chris Dennis singled to right field. Siegrist allowed one more hit, walked two and struck out two.
Oscar Taveras gave the River Bandits the lead with a one-out RBI single in the eighth. The slim lead held up as Quad Cities posted back-to-back wins for the first time in two weeks.