HOUSTON -- The Astros still have plenty of uncertainty surrounding their pitching, but their 8-5 win over the Cardinals on Tuesday night at Minute Maid Park did provide this reminder: good things can happen when the lineup comes together.

Injuries have overcome the pitching staff -- the latest blow arriving in the middle of this game, when starter Spencer Arrighetti exited with a left calf contusion -- but the offense did just enough, breaking out with a four-run third that proved to be crucial later, when the lead was much less comfortable.

“Those at-bats allow us to tack on -- add some insurance runs … put pressure on the defense,” manager Joe Espada said. “That's the kind of style of baseball that I know that we’re capable of playing.”

Yainer Diaz, similar to the night before, was the centerpiece of this win. He launched a three-run homer off Cardinals starter Andre Pallante in the third that traveled a projected 350 feet to right field, per Statcast, and put the Astros ahead, 6-1. Diaz, who was benched for two games during the prior series against the Twins and has struggled at the plate for much of the season, has homered in consecutive games, driving in five runs.

Any homer would be encouraging, but the fact that this was an opposite-field shot added to the enthusiasm of the moment, providing Diaz with even more proof that he is starting to feel more comfortable at the plate.

“When I started playing baseball, that's one of the things I was taught -- to try to drive the ball to the opposite field,” he said. “It would give me a lot more control to reach a lot more pitches. When I hit the ball hard the opposite way, it gives me confidence that I’m doing things right.”

Nine Astros hitters batted that inning. Alex Bregman led off with a walk, followed by a base hit by Yordan Alvarez. Jeremy Peña doubled home Bregman, and Diaz cleared the bases with his three-run shot.

“Everybody contributed up and down the lineup,” said Bregman, who suffered a left hand contusion after being plunked in the first inning by a Pallante pitch but stayed in the game. “Guys going first to third, Diaz hitting the big home run for us.

“That was the plan going in -- just trying to get a pitch to hit. We didn't want to chase. Guys did a good job of swinging at pitches that were over the plate and taking the balls.”

Not all the news was good. Arrighetti was struck on his left calf by an Iván Herrera line drive in the second inning, and though he stayed in through the third inning, he did not come out for the fourth, replaced by Tayler Scott.

The Astros have very little margin for error in their rotation -- they are facing losing both Cristian Javier and José Urquidy for the rest of the season -- and their depth could be further tested if Arrighetti is sidelined, even briefly.

But Arrighetti and Espada were equally emphatic that this setback will not linger into the right-hander’s next scheduled start.

Arrighetti said “it definitely shocked me a little bit” when the ball hit his leg. He recovered enough to make the throw to first to get the out, and initially, he felt like he could keep pitching.

“We had a medium-long inning, and then a long inning, and then it kind of just continued to get tighter,” he said. “So it just wasn't worth pushing it. But I think I’ll be just fine.”

Said Espada: “He came in in that third and said, ‘Joe, it's preventing me from finishing my pitches.’ And I said, ‘Well, you know what, that's enough.’ But I think he’ll be fine [for his next start].”

The game was delayed by seven minutes after the end of the fifth, due to an Astros staff member receiving medical attention in the dugout.

When play resumed, the Cardinals started to mount a comeback, beginning with rookie Masyn Winn -- a Houston-area native who grew up attending games at Minute Maid Park -- hitting a two-run homer off Parker Mushinski.

The Cardinals tacked on a run in the seventh behind a Nolan Gorman home run, but that would be the closest they would come to taking the lead. Victor Caratini’s sacrifice fly in the seventh put to rest any further threats of a Cardinals comeback.

With closer Josh Hader getting the night off, Ryan Pressly pitched a perfect ninth for his first save of the season.

The lineup will need more games like this if the Astros are to stay afloat in the AL West race. History suggests this is an area the team can depend on.

“I feel like over the course of 162 [games], the cream always rises to the top,” Bregman said. “Our offense is an elite offense. It has been for nearly a decade now. I feel like I trust everybody in here is gonna work their tail off and continue to battle every single day, and I think guys are doing a good job of that.”