Santiago allowed a lone hit -- a sixth-inning single -- and struck out a career-high nine batters over eight sparkling innings to lead the Double-A Birmingham Barons to a 4-1 victory over the visiting Chattanooga Lookouts.
"This was, by far, the best game I've had as a pro," the southpaw said. "I was excited to be out there and I was hoping for the ninth, but it wasn't to be."
The 23-year-old set down the first 16 batters he faced before issuing a one-out walk to Jessie Mier in the top of the sixth inning. Mier advanced to second on a balk and Ivan Ochoa broke up the no-hit bid with a single to center field. Brad Coon followed with a walk to load the bases, but Santiago retired the final two batters to strand all three runners and keep the Barons' 2-0 lead intact.
"I realized I was perfect through four, but then I didn't really pay any attention to it," the Chicago White Sox prospect said. "Then I fell behind 2-0 [to Mier] in the sixth, and I told myself to settle down and throw strikes. But I walked him and then gave up the hit and then walked another guy. It was huge to get out of that inning."
Santiago recovered from the lapse quickly, working two more perfect innings before reaching 108 pitches and turning over a 4-0 advantage to the bullpen in the ninth.
"My arm felt fine and I had that much energy and momentum," the New Jersey native said. "In games like this, you always hope for one more. I threw 103 pitches my last two games and I had never thrown more than 100 before, so I wasn't planning on throwing 100 again, but it worked out."
Santiago -- who throws a fastball, a change-up, a slider and the screwball -- kept hitters off balance all night in just his second Southern League start, in large part because of the pitch he only started throwing before Thanksgiving.
"I threw everything for strikes and I was throwing off-speed pitches early in the count, sliders on 3-2 and screwballs in and out," he added.
"I didn't have a change-up when I first came into pro ball, but I went to play Puerto Rican Winter Ball with [Gigantes de] Carolina. I was playing with Angel Miranda, who said I had a great arm slot from the left-hand side and eventually that developed into a change-up. My pitching coach there asked me to try throwing a screwball, and when I did, it had a lot of drop and there was a big difference in velocity. It became an out pitch and he just told me to keep throwing it as much as I can."
With Monday's victory, Santiago improved to 4-3 overall and 2-0 in two Double-A starts. He had a 3.68 ERA and 43 strikeouts over 44 innings in eight starts with Class A Advanced Winston-Salem before his promotion. In his Southern League debut Wednesday, he allowed three runs on seven hits and three walks while striking out six over 6 1/3 innings in a 5-4 win over the Carolina Mudcats.
"I'm pretty sure it won't always be this easy," Santiago said of moving up. "I haven't had to shake [catcher] Josh Phegley off in two games, so it's pretty nice to just go right after hitters.
"If I keep throwing first-pitch strikes and getting early outs I'll be okay. Strikeouts are awesome, but first-pitch ground balls are even better."
Charles Shirek lost the shutout when he allowed one run on two hits, a walk, a wild pitch and a passed ball in the ninth.
Phegley finished 2-for-4 with a pair of doubles and two RBIs.