After winning the opener 3-1 and ending the Astros' 11-game winning streak, the Tigers took a 2-0 lead into the sixth of the seven-inning nightcap.
“I went up to the plate with a plan to look middle or middle-away,” Alvarez said. “I got one on the 3-2 pitch and I put a good swing on it.”
Two pitches later, Correa hit a ball over the Tigers bullpen for the lead.
“It's very impressive to see a kid of Yordan's age work a count and hit the ball that far,” he said. “Then I was able to hit one and give us the lead. That's huge with the arms we have in our bullpen.”
Nomar Mazara doubled off Lance McCullers Jr. with one out in the Detroit sixth, but Ryne Stanek came in to retire the next two hitters. Ryan Pressly struck out the side in the seventh for his 12th save.
“Ryan Pressly has my All-Star vote and that inning is why,” Astros manager Dusty Baker said. “He comes in and does the job with no drama. Stanek did the same thing, which is what you want from your bullpen."
McCullers (5-1) allowed two runs on five hits in 5 1/3 innings.
“I had great stuff, but they got a couple of bloop hits against me,” McCullers said. “We got a great win and now I can move on to the next start.”
“We had it set up exactly how we wanted it,” Tigers manager A.J. Hinch said. “Wily and Funk got us to the point where we could bring in the back end of our bullpen. It just didn't work out.”
In the first game, Zack Short's first home run in the majors broke a fifth-inning tie for Detroit.
Casey Mize (5-4) improved to 2-0 in his last four starts, giving up one run on six hits and two walks in six innings. He struck out five to beat the Astros for the second time this season.
The Astros were trying to tie the franchise record of 12 wins in a row. They got off to a good start, as Altuve began the game with a single and took third on Michael Brantley's single.
Mize, though, struck out Yuli Gurriel and Alvarez before retiring Correa on a comebacker.
Jose Cisnero pitched the seventh for his third save.
Short, called up as Detroit's 27th man for the doubleheader, had his first career extra-base hit on a third-inning double over center fielder Chas McCormick's head, then homered off Framber Valdez in the fifth.
Valdez (4-1) lost for the first time in six starts this season, allowing three runs on six hits in a six-inning complete game. He struck out six without walking a hitter.
The Tigers took a 1-0 lead in the second on Isaac Paredes' sacrifice fly, but Correa tied the game with an RBI single in the third.
In the fifth, Paredes led off with an infield single, took second on Jake Rogers' sacrifice bunt and scored when Short hit a 1-1 changeup just over the right-field fence.
Astros: Recalled RHP Andre Scrubb to be the 27th man for the doubleheader.
Tigers: Recalled Short to serve as the 27th man. Short came into the game with three singles in five career games, and could stay up to fill Detroit's shortstop weakness.
Nearly seven inches of rain fell at Comerica Park between Friday and Saturday morning, causing flooding on many local streets and freeways. However, the field was ready to go for the 1:10 start of the opening game.
Southern Michigan was hit by more storms on Saturday afternoon, but they stayed north of downtown.
Hinch limited Peralta to nine hitters so that he can start again in Cleveland on Wednesday on three days' rest.