After taking two of three from the first-place Reds, the Phillies completed back-to-back sweeps of the Rockies and the Marlins and now face what is, on paper, a much easier task in the last-place Astros, who hold baseball's worst record.
Philadelphia blew the four-game series opener in Houston to end its seven-game winning streak, losing ground in the National League Wild Card race when St. Louis won at Los Angeles.
"It feels good to know that we're still playing for something and we've got a chance," said Phillies manager Charlie Manuel. "We're definitely right in the middle of it. It feels good. We've had some help from other teams, of course, and teams have been beating one another. We've been able to put together a streak and put us in a position that we're still in it."
The Phillies have won 15 of their past 20 and will look to get back on track as they send southpaw Cole Hamels to the mound, who is searching for his first win in nearly a month.
After tossing two complete-game shutouts in early August, Hamels has now gone three consecutive outings without a decision and is 1-0 with a 3.71 ERA in his past four starts.
Hamels (14-6, 3.03 ERA) has thrown more than 100 pitches in each of his past 14 starts and will need all his juice again Friday as he faces off against a rejuvenated Edgar Gonzalez.
Bud Norris was originally slated to start Friday, but the Astros chose to skip him due to a blister on his throwing hand.
Gonzalez, who had a seven-year stint in the Majors from 2003-09, was signed by the Astros out of the Mexican League. Since being promoted from Triple-A Oklahoma City, the 29-year-old righty has posted a 2-0 record with a 1.74 ERA in two road starts.
"I'm so excited and I've just been working a lot more, extra work every day in the gym and outside running a lot," Gonzalez said. "[I feel] much better. I'm more mature and have more experience. I'm 29 now and I feel much better."
Gonzalez has allowed seven hits and struck out 11 in 10 1/3 innings this season.
Phillies: Frandsen back in starting lineup
Third baseman Kevin Frandsen made his return to the starting lineup Thursday.
Frandsen, who hadn't started the previous seven games with soreness in his left ankle, knocked an RBI single in the third inning that put the Phillies ahead, 4-0, before they eventually faded in the eighth inning.
Frandsen is now batting .338 with 10 RBIs on the year since being called up in late July.
Jimmy Rollins recorded the 400th stolen base of his career Thursday night, swiping third base in the top of the eighth inning.
Rollins drew a two-out walk off Astros reliever Wesley Wright and advanced to second on a single by Carlos Ruiz.
Rollins caught Wright napping on the mound and slid into third under the tag. Rollins chalked up his 2,000th career hit last Tuesday in Cincinnati.
Astros: Club could impact races
While the playoffs aren't in the picture this season in Houston, the Astros could play as big of a role in the playoff race down the stretch.
The Astros are in the midst of a four-game stretch with the Phillies. In their 15 games remaining after this series, the Astros play the Cardinals six times, the Pirates three times and the Brewers three times.
Reliever Mickey Storey, who was struck in the right side of his face by a line drive in the eighth inning of Wednesday's game against the Cubs, suffered only a few bruises and could be ready to return to action soon.
Storey also didn't anticipate the incident bothering him in the future.
"It could have been a lot worse," he said. "I don't feel like it will be a problem at all. That's something that goes along with it. I have pitched for a long time and I don't think I ever had a comebacker hit me above the foot. It's one of those things that happens every now and again."
The three runs given up by the Phillies bullpen Thursday snapped a 21-inning scoreless streak.
The Astros are two losses away from 100 for the second straight season. Last year was the first 100-loss campaign in franchise history.