Rodriguez earned his second win of the season after recording 3 1/3 hitless innings in relief of Gonzalez, who tweaked his hamstring while fielding Garrett Jones' weak ground ball for the first out of the second inning.
"Fernando Rodriguez really stepped up today," DeFrancesco said. "He got some big outs for us, filled some innings for us. He made some pitches."
Rodriguez said it took him a little while to get warmed up for his appearance. He ended up throwing 43 pitches, tied for a career high. His 3 1/3 innings were also a career high.
"As soon as it happened, we got our heads up in case the phone rang, in case they took him out," Rodriguez said. "It's always nice when you're in those situations when you actually have a lead, too. These guys swung the bats well today, so we'll take it."
That early lead came courtesy of Jed Lowrie's three-run homer off Pirates starter Jeff Locke in the first inning, his 15th homer of the season. It was Lowrie's first homer since missing two months with injuries to his right ankle and leg.
"It felt great," Lowrie said. "I've been saying I've been feeling good at the plate, getting some hits and driving the ball, and [I] got in a good hitter's count and got a fastball and hit it out today."
Lowrie and his knee didn't escape Friday night unscathed, though. After Justin Maxwell hit his 17th homer in the sixth inning, Lowrie was hit squarely in the injured knee by a pitch from reliever James McDonald.
"It might be a little stiff," Lowrie said. "I've got that big ole knee brace on with all that padding, and it hits me right in the kneecap."
Lowrie scored on Brett Wallace's triple to give the Astros a 5-0 lead. Later in the inning with the bases loaded, Jose Altuve was hit by a pitch to plate another run.
In the seventh, Wallace hit a solo home run, his first homer at Minute Maid Park this season, off reliever Hisanori Takahashi. The last time the Astros hit three homers in a game was Aug. 14 at Wrigley Field.
"We have a lot of guys that can hit homers and drive in runs, and I think it's just a matter of us all getting on the same page and doing it every night together," Wallace said. "You've seen it throughout the year with Jed and [Maxwell] and if we can all get on the same schedule and start doing it together, I think our offense becomes that much more dangerous."
But even with a solid offensive night, the Astros would've been dead in the water if not for the bullpen's stellar performance.
After Rodriguez left the game after the fifth, Jose Valdez allowed the first three batters he faced to reach. Cedeno finished off the sixth by sandwiching a flyout and a strikeout around a walk.
Storey, Cruz and Lopez allowed one run -- a homer by Garrett Jones off Cruz in the eighth -- on two hits over the final three innings to seal the victory.
"They've got a lot of guys there with big upsides," Pirates manager Clint Hurdle said. "They've got big arms. You look at some of their numbers when they come in and say, 'Oh my gosh' -- but the arms are big, and when they're on, they play well."
Rodriguez probably won't get many opportunities to pitch more than a couple innings in the future, but he said his arm felt fine even after 43 pitches. He told pitching coach Doug Brocail that his last outing -- a 33-pitch performance on Tuesday -- might've helped him prepare for Friday.
"I'm built up already, so I have a few more pitches in me," Rodriguez told Brocail.
The Astros are 9-10 in September after winning eight games total in July and August. DeFrancesco said he doesn't feel bad at all about spoiling whatever remains of the Pirates' postseason hopes.
"I'm just glad we got the first one tonight," DeFrancesco said.