Sure, he had hit a grand slam against these Astros here on June 26. But that was his first in the big leagues. So grand slamming was not the order of the day, he thought.
"I had two strikes on me," he said. "I was just trying to put the ball in play and hope we'd get one run.
"Throughout my career, I haven't been very good with the bases loaded. It took me five years to hit my first one, and I figured it would be another five years before I hit another one."
But not on this magical night. Despite the stunning blow of losing ace pitcher Ben Sheets after the first inning to a hamstring cramp, the Brewers came back from a 1-0 deficit with the help of Estrada's grand slam to bury the Astros, 9-1, and move into a virtual tie for first place in the NL Central with the Cubs.
"I was surprised," Estrada said. "It's something that I knew I wasn't good at with the bases loaded, and I probably got it in my head a little bit. But this was great. I knew it put us up good, and we're a pretty good team when we score some runs early."
Manager Ned Yost thinks they're a pretty good team because of the way players like Estrada are coming through lately. The veteran catcher was hitting .297 over the last 13 games before Tuesday.
"Johnny's like a lot of guys on our team right now," Yost said. "He's picking up his play when it counts. He's picking it up both offensively and defensively. He's really, really calling good games for us behind the plate."
And as dismal as it seemed when Sheets went out, the Brewers bullpen came through like gangbusters. Claudio Vargas (11-4) started it off by going four innings, allowing two hits and a walk and striking out two to take the victory.
Vargas allowed two hits when he came in cold in the second inning. But then he retired nine of the next 10 batters he faced, and the trio of Seth McClung, Derrick Turnbow and Greg Aquino were even more effective, not allowing the Astros a hit the rest of the way.
"Claudio's performance was huge," Estrada said. "I mean, I know my grand slam was big, but for him to come in cold like that and to fill those innings like that was so big. Claudio sucking up those innings was just as big."
"Claudio actually had the best stats against [the Astros] of anyone we had so it was a no-brainer to go to him," Yost said. "But our bullpen, all of them did a great job. We have enough pitching that when something [like Sheets' injury] happens, it's not just a disaster."
Vargas was nonplussed about his clutch performance.
"I've done it before," Vargas said. "I've come in in relief before. I felt good. I just tried to get loose and make my pitches. I didn't think about it [being so sudden].
"I don't necessarily like coming in like that. But if I have to do it, I have to do it, and I give it my best. I want to do whatever I can for my team."
That seems to be the theme for this team, which has won four straight, has gone 11-5 in September and seems to be fully recovered from a mind-numbing 9-18 August just when it counts the most.
"I was telling the guys when we came to Houston," Estrada said, "that whoever puts together a seven-game streak right now is probably going to go ahead and win it. Hopefully we can continue to put this together."
Ryan Braun started the big fourth-inning onslaught with a triple that bounced up Tal's Hill in deep center field. He was driven in by Prince Fielder, whose single gave him a 16-game hitting streak.
Braun then hit a two-run homer, his 31st of the year, to make it 7-1 in the fifth. Geoff Jenkins and Rickie Weeks hit back-to-back homers in the ninth to top off the night.
Jim Carley is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.