CINCINNATI -- It took only four pitches for Luis Ortiz to flash triple digits on the radar gun in his Major League debut.

As it turned out, the 23-year-old right-hander was just getting warmed up. Ortiz, the Pirates’ No. 30 prospect per MLB Pipeline, turned in 5 2/3 shutout innings, allowing one hit while striking out five in the Bucs’ 1-0 victory over the Reds at Great American Ball Park in Game 2 of Tuesday’s doubleheader sweep.

Ortiz was in complete control throughout his outing, relying on two pitches: his slider and his four seam fastball -- the latter of which touched triple digits six times and averaged 99 mph.

“My mind has just been positive throughout the day,” Ortiz said through interpreter Mike Gonzalez. “My mindset and my plan was always to attack the zone, and I just remained faithful to the plan. I’m glad the results came through.”

While it was his fastball that got the most attention, his ability to mix in his wipeout slider was what made the difference. He received whiffs on half of the Reds’ swings on it (eight of 16), including multiple for swinging strike threes.

Ortiz’s lone hit allowed was Stuart Fairchild’s double in the third inning, and the only true scoring threat for the Reds came after back-to-back walks in the fifth. Both instances he worked around to keep Cincinnati off the board in a shutout win.

When manager Derek Shelton made the move to the bullpen, Ortiz had hardly slowed down. He even fired a parting pitch at 99.9 mph to Donovan Solano before putting him away with a slider to cap off his outing.

“This is something I’ve been working [on] my entire career,” Ortiz said. “Whether it's throwing 99 [mph], 100 [mph], less, it's always just making sure I’m commanding the ball right and attacking the zone exactly where I want. … I’m very grateful that the work is coming through and I was able to demonstrate it here [in] The Show.”

It’s been a while since the Pirates have had a starting pitcher with Ortiz’s velocity. His 100.4 mph fastball to Solano in the first inning was the fastest pitch by a Pittsburgh starter since five-time All-Star Gerrit Cole on July 5, 2015.

While it’s often a concern that a young arm can overthrow in their big league debut, the opposite was true for Ortiz.

“He handled himself really well,” Shelton said. “He never got too high, never got too low. He was in control. He had a couple of walks, which he pitched around. Overall, just [an] unbelievable debut. Really good job.”

After Ortiz departed, Chase De Jong, Yohan Ramirez and Duane Underwood Jr. quieted Cincinnati’s lineup over the final 3 1/3 innings, joining forces to log a one-hit shutout.

Underwood, who competed with Ortiz during a rehab assignment at Double-A, said he knew immediately that he was special.

“Just his poise. The way he attacks the zone, the way he attacks hitters, his mentality. He doesn't really come off of Plan A, and that’s tough to do,” Underwood said. “He attacks the zone, he’s fierce, he’s a competitor and I really enjoyed watching him today.”

It’s been quite the week for Ortiz. Only five days after being named International League Pitcher of the Week at Triple-A Indianapolis for firing six no-hit innings, Ortiz got the news that he would make his Major League debut in Cincinnati. The news also landed on his mother’s birthday.

Ortiz was originally signed as an 19-year-old in October 2018 for just $25,000 out of San Pedro de Macoris, Dominican Republic. After a middling first season in the organization, Ortiz wowed coaches with his high-velocity fastball during Spring Training. Following a promotion to Triple-A Indianapolis on Sept. 1, Ortiz pitched only 10 innings before receiving yet another promotion -- this time to the big leagues.

“[GM Ben Cherington] talks about identify, develop and deploy, and that’s what we did there,” Shelton said.

Per the rules regarding the 29th man of a doubleheader, Ortiz is required to be sent back down to Indianapolis after the game. That being said, he’ll give Pittsburgh plenty to consider when mapping out their 2023 rotation. At the very least, he’s earned another start during the final stretch of the season.

“I understand how people would be excited about that. I think people should just be excited he’s a Pirate,” Shelton said. “He’s 22 years old and was pitching in [Single-A] last year. This is a really good job with our development team, because this is a kid who has come pretty fast.”