Jose Altuve kicked off the seventh-inning rally by reaching on a throwing error by Phillies third baseman Michael Martinez. Jimmy Paredes and pinch-hitter Brandon Laird drew walks, loading the bases with one out for Justin Maxwell.
Maxwell's bloop double to right field off reliever Phillippe Aumont scored Altuve and Paredes to give the Astros a 5-4 lead. The ball barely hit inside the right-field foul line.
"Sometimes you get lucky," DeFrancesco said.
Matt Dominguez, the next batter, hit a high chopper over Martinez's head into left field, scoring Laird and Maxwell. The Astros ended up needing the insurance runs.
Domonic Brown's two-run double in the eighth off Astros reliever Mickey Storey brought the Phillies to within a run at 7-6, but reliever Wilton Lopez recorded a five-out save to seal the win.
DeFrancesco took full advantage of his expanded roster in the victory, making double-switches, sending pinch-hitters to the plate and using six pitchers. He also called for three intentional walks -- two to get to Ryan Howard, and the other to avoid facing him in the ninth inning.
The first one worked, the second didn't and the third resulted in the game's final out -- a weakly hit grounder to first by Carlos Ruiz.
"It's always fun when they work out," DeFrancesco said. "You look real smart. But there's days it doesn't work out. That's part of baseball."
DeFrancesco is certainly enjoying his time leading the Astros, who are 8-7 in September and 9-17 since Brad Mills was relieved on Aug. 18.
"It's just something that I've dreamed about my whole life," DeFrancesco said. "Now that I'm living it, it's really a nice place to be."
The Astros had some success against the Phillies' Roy Halladay.
Scott Moore's two-run homer in the third gave Houston a 2-1 lead. After the Phillies retook the lead with a three-run fifth, Carlos Corporan hit a long solo homer in the sixth to cut the deficit to one at 4-3.
"It's kind of an odd team to pitch to," Halladay said. "Sometimes they're aggressive, sometimes they're not. I think the whole series, we never really figured out what their plan was. That made it tough."
Halladay allowed three runs in six innings. He struck out seven and walked two. Maxwell, who extended his hitting streak to 10 games with the go-ahead double, said it was tough trying to get something going against Halladay.
"He really hits his spots and he throws any pitch in any count," Maxwell said. "Hats off to [starter Jordan] Lyles and the rest of our bullpen for keeping us in the game and giving us a chance to come back."
Lyles allowed four runs in five innings, walking four (two intentionally) and striking out six. The 21-year-old right-hander has run into trouble in the fifth inning all season.
"The fifth was another fifth for me," Lyles said.
After singling with two outs in the fifth, Jimmy Rollins stole second and moved to third when catcher Corporan's throw bounced into the outfield.
Juan Pierre plated Rollins with a double. The Astros intentionally walked Chase Utley for the second time in the game to face Howard, who doubled to left field to score Pierre and Utley and give the Phillies a 4-2 lead.
Lyles' ERA in the fifth inning this season rose to 15.83.
"It's definitely not mental," Lyles said. "After the game, you can say, 'Hey, that's another fifth.' To be honest, when I go out there for the fifth, [the] number five isn't stuck in my head."
The Astros have 17 games left in their season. After the game, DeFrancesco talked to his team about how the 1972 Dolphins went 17-0. Expecting that kind of finish may be overzealous, but DeFrancesco wanted to emphasize that there are lots of games left in which his young team can improve.
There was only one problem: the Astros are indeed a young team.
"Nobody knew anything about the '72 Dolphins," DeFrancesco said, smiling.