PITTSBURGH -- Pirates rookie Adam Frazier didn't shy away from playing a guessing game when he was brought in to pinch-hit in the seventh inning Sunday.

He guessed right and hit a tiebreaking home run to lift Pittsburgh past the Philadelphia Phillies 5-4 at PNC Park.

The solo shot, off reliever Edubray Ramos (1-1), was Frazier's first major league homer.

"It was up and in. I figured he was coming back with a fastball after just missing with two off-speed pitches," Frazier said. "I got my hands to it and got the barrel out front.

"It felt good. I haven't had one that felt that good all year. I've come close a few times. It's not who I am, so I'll take them when I can get them. I was pretty excited to see the ball clear the fence. In a tie game, I was just trying to do whatever I can. It was pretty big."

The Pirates won for the third time in four games and the fifth time in their past seven. They have won four home series in a row.

The Phillies are 1-8 in their past nine games at PNC Park.

The game featured a matchup of promising young starters, and both pitched six innings and left with the game tied 4-4, so neither got a decision.

Pittsburgh's Jameson Taillon allowed four runs on eight hits. He walked none and struck out seven, the highest total in his 11 starts during his rookie season. Taillon had allowed two earned runs in 12 innings over his previous two starts.

Philadelphia's Vince Velasquez, who had been 3-0 with a 1.88 ERA in four starts since coming off the DL in late June, allowed four runs on seven hits with four walks and five strikeouts.

"Just looking at his body language, he showed that he was struggling to find the strike zone," Philadelphia manager Pete Mackanin said. "He didn't have his best location. ... Obviously, he wasn't at his best, but he kept us in the game."

Velasquez said he didn't have great control with his curveball, and he had some trouble with the muggy day with temperatures around 90.

"You're going to go through various conditions, and it's something that you've got to really take into consideration -- to really lock in, stay hydrated because it can mentally drain you," he said. "It kind of took a toll on me, but I have to make the best of what I've got."

Neftali Feliz (4-0) pitched a scoreless seventh for the win. After Tony Watson handled the eighth, Mark Melancon pitched a perfect ninth for his 30th save.

Third baseman Andres Blanco -- who left in the fifth after his left index finger was broken and bloodied on a fielding play and is likely headed to the disabled list -- hit a two-out home run to center to give Philadelphia a 1-0 lead in the first.

The Pirates took a 2-1 lead in the second on Elias Diaz's one-out groundout -- his first major league RBI in his first major league start -- and Sean Rodriguez's RBI double to center after Starling Marte singled, Matt Joyce walked and both advanced on a Velasquez wild pitch.

The Phillies leapfrogged back in front, 3-2, in the third. Cesar Hernandez tripled to center to drive in Velasquez, who opened with an infield single. Hernandez scored on Odubel Herrera's groundout.

In the sixth, Herrera's leadoff homer to center, his 11th, boosted Philadelphia's lead to 4-2.

"The two home runs were both three-fastball sequences," Pirates manager Clint Hurdle said. "(Taillon) was trying to throw a two-seamer that carried back over the plate for one of them and an elevated four-seamer that caught too much of the plate. Opportunities to learn. That two-seamer needs to play or maybe something in an offensive count that he needs to change up,"

Joyce pulled Pittsburgh into a 4-4 tie with a 434-foot, two-run home run, his 10th, to dead center in the sixth.

Velasquez kicked himself for giving up a double to Marte on an 0-2 pitch just before Joyce's home.

"That's just a matter of finishing at-bats," Velasquez said. "You've got to lock in on 0-2 counts when you're ahead. You've got to finish the at-bat.

"Knowing that that was my last inning, that's where you have to bear down and give it all you've got."

NOTES: There was a 92-minute rain delay in the bottom of the eighth. ... Pittsburgh placed RHP Tyler Glasnow on the 15-day disabled list, a day after he left his second major league start in the fourth inning because of right shoulder discomfort. ... C Cameron Rupp, who was hit in the cheek by a pitch Saturday, was out of the Philadelphia lineup. It is believed he is undergoing concussion protocol but had shown no symptoms. ... Phillies 3B Maikel Franco (left wrist) missed his second straight start, but he entered and went 1-for-2. ... RHP A.J. Schugel was recalled from Triple-A Indianapolis, one day after he was optioned there by the Pirates to make room for Glasnow. ... Pirates CF Andrew McCutchen and C Francisco Cervelli, who is coming back from a broken hand, were given the day off. ... Pittsburgh and Philadelphia don't meet again until a three-game series Sept. 12-15 at Citizens Bank Park.