Bregman tripled to right-center in the first inning and scored the game's first run. He then lined a double to left in the third -- which had an exit velocity of 107.2 mph according to Statcast™ -- and singled in the fourth.
Bregman also made a nice play at third base to end the fourth inning and save a run before moving over to shortstop.
Here's where it gets interesting. In the seventh and ninth innings, Bregman came up going for the home run that would have completed the cycle.
"The guys were all over me," he said. "I had to go for it. If I'd taken a walk and looked at strike three, I wouldn't have heard the end of it."
"I told him I wanted to see it off the third deck of the Western Metal building," said Joe Musgrove, Bregman's Fresno teammate. "He's one that can do it."
Meanwhile, Musgrove, a Southern California native who started for the U.S., pitched a scoreless first inning in front of family and friends.
"This was such a special day for me," he said.
Back to Bregman. He popped up in the seventh inning, then came to bat in the bottom of the ninth against Giants prospect Adalberto Mejia.
Bregman has a history with Mejia. On the Fourth of July, he hammered a changeup out of the park in Fresno.
"I didn't think he'd throw me another change," Bregman said.
Mejia didn't. He struck out Bregman on a curveball. All in all, though, it was an amazing day.
"Honestly, I was just trying to take it pitch by pitch and enjoy this moment," he said. "Not everybody gets to have this opportunity. We're all honored to be here. I was trying to have fun.
"I'm excited for the future. I want to help the Astros win games now. I want to help them win in the postseason. I feel like I can help contribute, and whenever that time comes, I'll be ready."
Bregman tripled off Cardinals prospect Alex Reyes, who mixed in two curveballs with fastballs that were clocked at 97, 101 and 98 mph. He got the triple off the 98-mph heater.
"Reyes has an unbelievable arm," Bregman said. "It was cool to face him. You've got to want to compete with the best of the best and when the pressure's on."
Bregman's big day comes at a time when the Astros are contemplating when to add him to the big league club. Since Houston made him the No. 2 overall pick of the 2015 Draft out of Louisiana State, Bregman has passed every test with flying colors. He has played so well that he seems likely to be a second-half boost for the roster of a team that has sprinted its way back into contention.
After a 17-28 start, the Astros have gone 31-13 and cut their deficit in the American League West from 10 games to 5 1/2, sitting in second place behind the Rangers.
Bregman said it would be "a dream come true" to be able to contribute to an Astros postseason run in 2016.
First things first.
"One of the things we talked about during the offseason back home was be where your feet are," Bregman said. "If your feet are in Fresno, Calif., that's where your head needs to be. That's where your mind needs to be. You don't need to be thinking about anything else other than the next game you're going to play. That's the mentality I've been taking."
Bregman hit .297 in 62 games at Double-A Corpus Christi this season and is hitting .389 in eight games at Triple-A Fresno. He has 19 doubles, 19 home runs and a 1.019 OPS in the 70 games.
All of which leads to one question for Houston: When will Bregman play for the Astros? General manager Jeff Luhnow has said only that he believes Bregman will contribute to Houston at some point in the second half of the season.
Although Bregman has played all but eight games at shortstop this season, he won't play there in the big leagues because of Carlos Correa's presence. However, he played eight games at third base at Double-A and takes ground balls there every day at Triple-A.
"I'll play wherever they want me to play," Bregman said. "Anywhere on the field. Do anything to help the team win. Whether that's playing left field or third base or wherever, I don't care. That would be a dream come true to be able to play postseason baseball with the Astros this year."
If Bregman plays third -- which seems likely -- it would mean Luis Valbuena would move across the diamond to play first. Either way, Bregman said he's focused on doing his job at Triple-A and being prepared when the opportunity comes.
Growing up in Albuquerque, N.M., Bregman's favorite player was Derek Jeter. In terms of preparation and potential, the Astros think that's a good comparison. Only question is when they'll begin writing the next chapter of his story.
Richard Justice is a columnist for MLB.com. Read his blog, Justice4U. This story was not subject to the approval of Major League Baseball or its clubs.