The Rays prospect tossed the first no-hitter in Bowling Green's three-year history, striking out a career-high 10 as the Hot Rods completed a doubleheader sweep of the Lake County Captains with a 1-0 victory.
The strikeouts were a personal best for Mateo (9-4), who completed the longest outing of his five-year Minor League career.
"I was very happy, it was great," he said. "Greatest night of my life."
Mateo issued a leadoff walk to LeVon Washington in the first, then retired the next 17 batters, nine on strikeouts. As the 21-year-old right-hander was mowing down the Captains, he realized he had a chance at history.
"In the fourth inning, I was thinking about it," Mateo said. "I looked up and saw they didn't have a hit, so I was gonna try to get it."
The heat of the moment helped push Mateo to overcome a lackluster pregame bullpen session.
"Pitching in between the lines, the emotions are a lot bigger," he said.
Mateo's biggest trouble spot came in the sixth, when he issued two more walks to put runners on the corners with two outs. But he got Alex Monsalve to ground out to keep the no-hitter intact.
"I always thought when I saw big leaguers throw no-hitters, every no-hitter has good plays behind it," Mateo said. "No-hitters can't be strikeout, strikeout, strikeout. Your team has got to help you, making great plays behind you."
Mateo worked a 1-2-3 seventh to end it, catching the final out himself.
"It was the biggest emotion I ever had on the field," he said. "It was like nothing before."
Signed by the Rays as a free agent in November 2006, the native of the Dominican Republic has a 4.55 ERA with 77 strikeouts in 87 innings. He has been hot of late, going 3-0 with a 1.69 ERA in his last five outings.
Now approaching his innings limit, Mateo said he does not have lofty goals for the rest of the season.
"Just try to go easy because they told me I'm running out of innings," Mateo said. "I'm gonna pitch 125 innings. I'm gonna start throwing three or four innings.
"I'm gonna try to keep working like I was. I'm just focused on one pitch at a time."