Rienzo surrendered five extra-base hits -- including three home runs -- and threw two wild pitches over six innings but still avoided his first career loss as the White Sox dug themselves out of an early hole but ultimately fell short.
After Chicago erased a five-run deficit to take an 8-7 lead in the sixth, Chris Carter delivered an RBI single in the seventh to tie it, and Matt Dominguez and Carter hit back-to-back homers off of Addison Reed in the ninth for a 10-8 lead.
It marked the first time in Reed's career that he gave up two home runs in an outing, and the closer has a 4.03 ERA (10 earned runs in 22 1/3 innings pitched) in non-save situations.
"I felt awesome out there," Reed said. "I felt great. I felt I had everything working and made a couple bad pitches. I hung a slider to Dominguez and he made me pay for it."
"I thought [the pitch to Carter] was a great pitch," said catcher Josh Phegley. "He put a great swing on it and drove it out of the park. There's nothing really you can do about it."
Trailing, 7-3, in the sixth, Adam Dunn hit a two-run homer -- his 30th of the season -- to cut the deficit in half. He became the second left-handed hitter in franchise history to have consecutive seasons with at least 30 home runs, joining Jim Thome, who did so from 2006-08.
Following a Jeff Keppinger single and Dayan Viciedo double, Phegley blooped an RBI single to center. Viciedo then scored on a balk by reliever David Martinez. Alejandro De Aza followed with another RBI single to put the White Sox ahead, 8-7. It was his fourth hit, tying a career high (July 20 vs. Atlanta).
A double-play grounder by Gordon Beckham in the third and a Keppinger homer in the fifth accounted for Chicago's other two earned runs. They would be gifted a run in the fifth when Astros right fielder L.J. Hoes dropped a Beckham fly ball that enabled De Aza to score.
The White Sox had two errors of their own, including one in the second inning with runners at first and second. Brandon Barnes singled to right field and Avisail Garcia let the ball roll under his glove and two unearned runs scored as he chased it down.
Chicago's miscues weren't limited to defense. In the first inning, De Aza stood at third with one out when Alexei Ramirez hit a chopper in front of home plate. De Aza initially broke for the plate and Astros starter Brett Oberholtzer threw to third to get him as he tried to get back to the bag. Then Ramirez, who had reached first on the play, was thrown out trying to steal second.
With the Astros leading, 3-1, Brett Wallace and Carter homered in the fourth and fifth innings, respectively. Wallace hit a solo shot and Carter, who hit a two-run homer, would not have had the chance if it weren't for Rienzo's first wild pitch, which came on a strikeout of Jason Castro, enabling him to reach first. The next batter popped out, and the inning would have been over.
The Astros' seventh run came on another Rienzo wild pitch, allowing Barnes to score from third in the sixth.
"[It was a] terrible game for me," Rienzo said. "I got hit really hard. … It was completely my fault. I [left] the ball up and the guys hit [it]. … [I will] just go to the next one and try to do better."
Rienzo's battery mate said that it was just a rough night for the rookie.
"Rienzo has thrown fantastic for us, and I think he just had one of those days where he didn't have his usual stuff and he battled out there as best as you could," Phegley said. "We had a plan but just didn't exactly execute it."
White Sox manager Robin Ventura agreed.
"[Rienzo] wasn't as sharp as he's been earlier by any means," Ventura said. "It's one of those that you just chalk it up to a bad night."
Astros manager Bo Porter said his hitters did a good job of laying off Rienzo's breaking balls to get to pitches they could drive.
"This guy threw a ton of breaking balls and a lot of them were out of the zone," Porter said. "They laid off a lot of the breaking balls down in the zone, which bought them some fastballs up. We did a good job putting some good swings on it."
The White Sox, who stranded three runners in the ninth when Garcia struck out looking to end the game, have dropped four of five games against the Astros this season. Prior to Monday's loss Chicago had taken two of three from the American League West-leading Rangers over the weekend and had won 14 of their last 20 games.
"That's kind of the story of our year," Reed said. "We look good one series and then do something like this."
But Ventura said he's not reading too much into the loss.
"I'm not going to judge anybody by tonight," he said.
Rienzo was glad his manager feels that way given his rough outing, and he's looking to get back on track in his next start.
"I'm glad [there is] no judging," he said.
Manny Randhawa is an associate reporter for MLB.com.