HOUSTON -- After scoring only one run in two games over the weekend at Cleveland, the Astros certainly faced an uphill battle against Rangers lefty Martín Pérez, who hadn’t lost a game in 19 consecutive starts and had shut out Houston on May 20.

And when Pérez mowed down the first nine Astros hitters he faced on Tuesday night at Minute Maid Park on only 23 pitches, things appeared to be playing out as expected.

The script was flipped suddenly in the fourth inning, beginning with a leadoff single by Jose Altuve, helped along by three walks by Pérez and capped by a grand slam by Aledmys Díaz that sparked the Astros to a 7-5 come-from-behind win in the series opener.

“When our team starts shrinking the zone, when we start swinging at strikes, there’s that passing-the-baton mentally and approach, and our offense is a pretty special one,” acting manager Joe Espada said. “That’s what we get. We start laying off some of those pitches in the corners. ... It was a big swing there by Díaz.”

Down 4-0, Pérez gave up a leadoff single to Altuve in the fourth and he walked three of the next four hitters before Díaz came to the plate. A double play off the bat of Yordan Alvarez put Perez one out from escaping, but Díaz crushed an 0-1 changeup and sent it a Statcast-projected 432 feet over the wall in left-center for his second grand slam of the season, tying the score.

“He’s got great stuff and he can come with a cutter, sinker, fastball in, so he just threw me the same changeup and I fouled it back. And I said stay through the middle,” Díaz said. “I put a good swing on it.”

Díaz is having the best season of his career and he is proving his value with his bat and his versatility. He’s started games at six positions -- 15 in left field and third base, 13 at second base, seven at shortstop and five at first base and DH -- and he is slashing .251/.306/.427 with 10 homers and 31 RBIs.

In 26 games since July 5, Díaz is slashing .309/.368/.629 with 10 doubles, seven homers and 17 RBIs.

“He’s been very valuable since the first day he got here,” Espada said. “He’s one of those players that sometimes goes unnoticed because he’s not your everyday guy. He picks you up defensively, gets you some big ABs, he’s a leader in the clubhouse. He’s been a very special player for us and he contributes in so many different ways.”

Alex Bregman said Díaz’s value to the team can’t be measured. Here’s one: Díaz is hitting .271 in wins and .231 in losses.

“He has been swinging the bat incredibly,” Bregman said. “He can play so many different positions, he’s so versatile. He’s a great defender. He’s just a good baseball player and a winning player … and he’s a great teammate.”

Espada said Díaz gets more comfortable the more he plays, and a prolonged injury to left fielder Michael Brantley has opened the door for more playing time.

“He’s got a very simple swing and once he gets on his legs and he starts recognizing the pitches he can handle, he’s a really good hitter,” Espada said. “Once he gets going, once he gets comfortable, once he feels like he’s part of the everyday offense, you start seeing some really good results.”

Díaz struggled to stay on the field his first two years in Houston because of various soft-tissue injuries, but he got himself in better shape and he has avoided the injured list the past two years, with the exception of breaking his hand when he was hit by a pitch last June.

“I’m feeling great,” he said. “I know it’s a long season. I have to be consistent. I have to do the same thing every time when I get to the park and go to the cage and work hard, and hopefully get on base.”

Díaz isn’t one to start campaigning for more playing time.

“That’s not my job,” he said. “I’m here to help the team win. If I have to play every day, I’m good with that. If I have to play three or four times a week, I’m good with that. I’m going to come every day to the park and be ready to be in the lineup. If not, I’m going to contribute from the bench. The real goal is to go to the playoffs and win the World Series.”