It was the ball he laced into right field for his first Major League hit in the third inning, which drove in Evan Gattis and gave the Astros a one-run lead in a game they'd eventually win, 8-5, over the Rockies.
"It felt really fantastic," a beaming Santana said. "Felt like a whole burden got off my shoulders."
Santana, rated the Astros' No. 3 prospect by MLB.com, finished 1-for-3 with a run while adding his first big league stolen base in the fifth. He was recalled on Monday to replace Colby Rasmus, who was placed on the bereavement list after Monday's game and will be unavailable for Houston's trip to Colorado.
The entire game lifted a weight for Santana, who had to live with his first two rough stints in Houston for nearly a year.
Over two callups last season, Santana went 0-for-17 with 14 strikeouts. He used Triple-A Fresno Grizzlies hitting coach Leon Roberts to learn patience and molded himself into a .300 hitter, earning Pacific Coast League Player of the Week honors. And he had reached base in 34 consecutive games when he was called up.
"From the beginning, I was confident," Santana said before the game. "But what happens happens. I'm just trying to take advantage of every little opportunity I get and go out there and just play."
"He looked way more confident than he did in the spring," manager A.J. Hinch added after the game. "Carried himself with some ease in this ballpark. Big at-bats, nice to see him get his first hit and smile on a Major League field. I thought he handled himself well."
Hinch was more impressed with a defensive play, where Santana and center fielder Jake Marisnick teamed to play a tricky hop off the left-field wall in the first inning, holding Rockies designated hitter Corey Dickerson to a double.
Santana said many deep thoughts ran through his head while on first base in the moments after the hit, thoughts of all the trials and tribulations he's endured.
But he made sure the ball was safe and kept in his locker. He has a special plan for it.
"I'm going to give it to my mother," Santana said. "I hope she keeps it safe. It's really, really special. A dream come true."
Chandler Rome is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.