"My first experience in a big league game, even though it was in Spring Training, it was a lot of fun to be with the players over here and play against the Washington Nationals," Correa said. "It was a really great experience for me."
Correa, 18, hit the first pitch he saw from Nats reliever Drew Storen for a game-tying single in the eighth before popping out in the ninth.
"I was going to be aggressive," Correa said. "Obviously, he left me a fastball in the zone and I swung at it and I got a hit. My plan was to be aggressive if the pitch was in the zone."
Astros manager Bo Porter said Correa shook his hand after the game and thanked him for the opportunity. Porter said he was impressed by how all three handled themselves on Saturday.
"You watch them go about their business, you watch them take ground balls, you watch them take batting practice," the manager said. "They're top prospects for a reason. They're highly talented young men. When you talk to them, they're mature beyond their years.
"They all came in when they came over today and spoke to me and they wanted to introduce themselves, even though I already know them. Ever after the game, we were in line shaking hands and the first thing [Correa] said is, 'Bo, thank you for this opportunity.' It shows you how much they appreciated it, and we're glad to have those guys in the organization."
Singleton was originally in the lineup at designated hitter, but Porter had to shuffle his order when the Nats opted to have pitchers hit. The slugger would have been in Major League camp for the second year in a row had he not been suspended for the first 50 games of the season after a second failed drug test.
"It's definitely a chance to leave a lasting impression, but I'm just going to go out here and play my game," Singleton before the game.
Santana, acquired along with Singleton, Jarred Cosart and Josh Zeid from the Phillies in exchange for Hunter Pence in 2011, hit .302 with 23 homers and 97 RBIs in 119 games at Class A Lancaster last season.