Philadelphia (47-37) has won four games in a row and six of its past seven to sit 10 games above .500 for the first time since late 2011.
"I think it's a nice milestone and one that we can celebrate. We'll use it as fuel and motivation," Phillies manager Gabe Kapler said.
The Phillies have put themselves in solid contention in the National League East. The series opener Friday against Pittsburgh launches a four-city, 11-game road trip that leads into the All-Star break.
"We never really doubted ourselves," said Phillies starter Aaron Nola, who picked up the win Wednesday in a 4-1 victory over Baltimore. "Other people thought we were in a rebuilding year this year. We got good additions to the team.
"We have veteran guys who have been on winning teams and won championships. They know what it takes to win, and I think we're following them."
The Pirates (40-46), meanwhile, sit at a season-low six games below .500 and are in danger of being caught by last-place Cincinnati in the NL Central. They are opening an 11-game homestand leading into the All-Star break.
Pittsburgh is coming off a 2-4 West Coast trip, the final three games of which it was swept in Los Angeles by a combined score of 31-8. The Dodgers had 10 homers among 41 hits in those games.
"I think we definitely could have played better, but we also ran into a really hot team too," Pirates shortstop Jordy Mercer told MLB.com. "In the whole grand scheme of things, we haven't played very well and we're six games under .500 right now. Things could be a lot worse.
"That's one of the bright spots that you can look at. ... We need to put four or five games in a row, and win four or five good games in a row, then see what happens after that."
The Phillies qualify as another hot team. They also swept a four-game series against the Pirates in April.
"We've just got to keep working," Pirates manager Clint Hurdle said. "The game shows you where you need to improve. It gives you immediate feedback. We got a lot of immediate feedback."
Two Pittsburgh starters, Chad Kuhl and Joe Musgrove, were hurt during the road trip.
On Friday, Pirates right-hander Trevor Williams (6-6, 4.22 ERA) is scheduled to start against Philadelphia righty Nick Pivetta (5-7, 4.66 ERA).
Williams has lost two straight starts since a June 18 win when he pitched seven scoreless, one-hit innings against Milwaukee. That was his first victory in more than a month.
He is 0-1 with a 3.86 ERA in two career starts against the Phillies, including a no-decision April 22 when he gave up two runs in six innings of an 11-inning Pirates loss.
Pivetta's last outing wasn't a start. He came in to pitch a scoreless 13th inning Sunday when the Phillies had to go deep into their pitching staff in a 4-3 win over Washington. It was his first relief appearance since 2015 when he was in Class A.
Pivetta has one no-decision in his career against Pittsburgh.