PITTSBURGH -- Pittsburgh used two big innings Saturday to beat Philadelphia, and they were big for different reasons.

In the fourth, the Pirates overcame an injury to starter Tyler Glasnow and kept the Phillies from breaking the game open. In the fifth, the Pirates scored five runs to secure a 7-4 win.

Gregory Polanco and David Freese each drove in two runs for Pittsburgh in the fifth.

Pirates right-hander Tyler Glasnow, making his second career start, left in the fourth because of right shoulder discomfort. He gave up two runs, one of them earned, and four hits in three-plus innings. The Phillies also stole five bases on his watch.

"He didn't notice or tell us or share anything with us until just visually we saw him moving his arm around like it was uncomfortable," Pittsburgh manager Clint Hurdle said. "We went out and talked to him and removed him."

Glasgow said the discomfort escalated from inning to inning but downplayed it -- "Just taking it day to day," he said -- and was reluctant to blame it for his performance.

"It's hard for me to come up here and tell everyone that my shoulder was bad, so I threw bad," Glasnow said. "I definitely wasn't 100 percent, but you're not going to be 100 percent a lot of games, you have to go out there and throw with what you have. I'm not blaming anything on anything. I just have to go out, feel better and do well."

Juan Nicasio (8-6) gave up a run in two innings in relief for the win. His biggest assist likely came in the fourth when he replaced Glasnow. He inherited two on, no outs and a 2-1 count on Peter Bourjos with the score tied 2-2. He got three outs in a row, including two strikeouts, to end the threat.

"That was big," said Josh Harrison, who tripled and scored the Pirates' second run in the second. "For one, you never want to see one of your guys come out due to injury. Nicasio came in and did exactly what we needed him to. At the end of the day, it gave us time to keep plugging away and we got to the fifth inning and were able to come up with a big inning."

In the Pittsburgh fifth, Polanco's bases-loaded, none-out single drove in two for the Pirates' first lead at 4-3. Freese later added a two-run single, and Francisco Cervelli's sacrifice fly made it 7-3.

The Phillies climbed within 7-4 in the sixth on Herrera's triple and Blanco's single.

Philadelphia countered with one of its own young pitchers in Aaron Nola (5-9), who gave up six runs on six hits in four-plus innings.

"I didn't have control of my curveball from the start, but I just kept falling behind and felt like I was 1-0 on everybody," Nola said. "I still thought I did OK until the fifth inning. I left a couple of balls up and over the plate in that inning and they made me pay with a couple of big hits."

Odubel Herrera was 3-for-4 with a walk and two runs scored for the Phillies.

The teams traded runs through the first couple of innings.

Philadelphia took a 1-0 lead in the first when Herrera walked, stole second, moved to third on Andres Blanco's single to left and scored when Teddy Joseph singled to right.

The Pirates responded in the bottom of the first when Andrew McCutchen doubled to the Northside notch with two outs and scored on Starling Marte's single past diving third baseman Blanco.

It was the Phillies' turn in the second. Freddy Galvis reached on Glasnow's fielding error, determined by a replay challenge, stole second and scored on Cesar Hernandez's base hit up the middle for a 2-1 lead.

In the Pittsburgh second, Mercer's groundout scored Harrison for a 2-2 tie.

Philadelphia didn't follow suit in the third but only because Glasnow escaped a threat.

The Phillies loaded the bases on a single and stolen base by Herrera, a walk an out later to Joseph and a pitch that hit Cameron Rupp up high.

Rupp crouched near the plate and received medical attention before leaving the game. He was replaced by pinch-runner Carlos Ruiz, who stayed in the game at catcher.

"He checked out fine," Philadelphia manager Pete Mackanin said of Rupp. "The (concussion) protocol is that he needs to be checked again the second day, so we'll know for sure (Sunday) if he's going to be OK, but I anticipate there not being any problems. The ball deflected off the ear flap and caught him in the cheek. We didn't want to take any chances so we got him out of there."

Glasnow got Cody Asche on an infield popup and Galvis on a grounder to end the inning.

The Phillies took a 3-2 lead against Nicasio in the fifth on Hernandez's two-out RBI single.

NOTES: RHP Tyler Glasnow was recalled from Triple-A Indianapolis and made his second major-league start for the Pirates. To make room for Glasnow, RHP A.J. Schugel was optioned to Indianapolis. ... Philadelphia 3B Maikel Franco was not in the lineup. He left Friday's game two innings after being hit on the left wrist by a pitch. The Phillies indicated he was experiencing soreness and nothing more serious. ... 3B Andres Blanco, who subbed for Franco on Friday, again started in Franco's place Saturday. ... Pittsburgh placed C Eric Fryer on paternity leave after his wife, Allison, gave birth to twins. C Elias Diaz was recalled from Indianapolis to fill in. ... Pirates RHP Ryan Vogelsong, who had facial surgery in May after being hit by a pitch, was eligible to come off the disabled list but did not because of neck stiffness. ... Pittsburgh manager Clint Hurdle declined to discuss any possible move down in the lineup for former MVP Andrew McCutchen, who is having a down season and was batting .244 entering the game.