"He is definitely one of the core pieces that will move forward with this organization," Astros manager Bo Porter said. "You look at the performance he had today, it's been consistent all year. Basically hitting in the 3-hole the majority of the year, he's had big hit after big hit. Tonight was no different."
On the other hand, the Astros roughed up Castro's soon-to-be American League All-Star teammate, Rangers starter Yu Darvish, as badly as any team has all season.
"It's obvious looking at today's performance, I didn't perform like an All-Star," Darvish said. "I should've been a little bit more aggressive."
Darvish got the win against the Astros in each of his three previous starts against them, including his near-perfect game in April. On Saturday, the Astros worked four walks off Darvish and tagged him for five earned runs, the most he's given up since Aug. 6 last year, in six-plus innings.
Jose Altuve, the last batter Darvish faced, drew a leadoff walk in the seventh. Then reliever Robbie Ross hit Brett Wallace with a pitch, bringing Castro to the plate. The catcher ripped a 427-foot homer to right field, his 12th of the season.
"He is really able to do pretty much anything at any time," Castro said of Darvish. "That mix is what keeps you off balance. You've got to be aggressive early, and when you get your pitch, you can't miss it or it's going to be a tough at-bat. We did a good job, guys getting some pitches out over the plate and putting them in play. It was a great job at the plate today with everybody."
Houston got on the board first with a pair of runs in the fourth. Mark Krauss singled and Brandon Barnes followed with a two-run homer.
The Astros aren't known for their power -- entering Saturday, they had the fourth-fewest home runs in the AL -- but three homers were more than enough to take down Texas, which hit two round-trippers of its own.
"We are a pretty young team, we're going to take our lumps here and there, but nights like this, it's a lot of fun, especially with the young guys contributing," said Krauss, who led Houston in hits in a 3-for-4, two-RBI night.
No. 9 hitter Jake Elmore even got in on the homer parade for the Astros, hitting his first Major League homer off Tanner Scheppers -- an AL Final Vote candidate -- in the eighth. Elmore's shot gave Houston some insurance and punctuated a satisfying win over a top team's top pitcher.
"We're rebuilding, everyone knows that, but we're not going to back down from anyone," Elmore said.
Astros starter Dallas Keuchel left after allowing back-to-back singles to start the sixth. Both runners scored on Geovany Soto's three-run homer off Wesley Wright.
The Rangers also got a solo homer in the seventh from Nelson Cruz, but five Astros relievers, including winning pitcher Travis Blackley and closer Jose Veras, combined to hold down the win.
Castro was the obvious hero of the day, but the Astros' resilience at the plate wasn't limited to their No. 3 hitter.
"Even in some of our losses where we've given up quite a few runs, we've had kind of that 'never say die' attitude and we've put up runs despite some bigger deficits," Castro said. "We've been able to do that a decent amount this year, and it's good to see, because we're definitely capable of scrapping back."