As the fifth inning unfolded Friday night, James McDonald's solid start slowly eroded under a barrage of San Diego Padres hits.
A long home run from Chase Headley became the exclamation point of the inning that ended McDonald's worst start this season.
The Pirates lost, 9-8, to the Padres at PNC Park in the latest tough outing for McDonald in a tough second half of the season.
By the time Headley's long home run drove him from the game with one out in the fifth, he had allowed seven runs on seven hits, the majority of the damage coming in the six-run fifth that transformed a 7-1 Pirates lead into a tie score.
"A starting pitcher's job is not to go four innings," McDonald said. "They got to go deeper in the game. When you've got a 7-1 lead, you've got to get hungry and get that job done, and I didn't do it.
"I let the team down today, big time."
McDonald has allowed 30 earned runs in 31 innings over six second-half starts, giving him an ERA of 8.71. He had a 2.37 ERA in the first half of the season. He said he could not identify what has led to the second-half issues.
"If I could, I would have turned it around after the first one a long time ago," he said.
"This is something a lot of players don't want to go through, but they have to sometimes. It's taking a little longer than what I want, but I just got to keep grinding."
McDonald threw six pitches to retire the side in the fourth and, at one point, retired 11 in a row, but he allowed the Padres to assemble a big inning in the fifth.
Cameron Maybin walked with one out and John Baker singled before pinch-hitter Jesus Guzman doubled off the wall in center to score two runs.
Alexi Amarista, who opened the game with a home run on the second pitch, singled to score Guzman, and Everth Cabrera singled.
McDonald grooved a fastball to Headley, who crushed it into the upper rows of seats above the Clemente Wall in right, tying the score at 7-7.
Manager Clint Hurdle said he believed McDonald could work out of the inning.
"If we can challenge him, if he can put a foot down and get through this, he can walk out of this with a positive building block," Hurdle said.
"If I yank him [in the fifth], it leaves doubt. The move I made did not work."
The Pirates briefly took the lead in the sixth. Garrett Jones walked and Pedro Alvarez singled before Rod Barajas' single drove Jones home, breaking the tie and giving the Pirates an 8-7 lead.
Headley hit his second homer of the game and 17th of the season off Tony Watson in the seventh.
That one scored Cabrera, who had walked, and gave the Padres a 9-8 lead, which stood up for their fifth victory in a row.
Two unusual trends continued for the Pirates: They surrendered multiple home runs and their bullpen struggled to keep runs off the board.
The Padres hit three home runs. The Pirates have allowed nine home runs in their past four games, and in three of those games, one player hit two home runs.
The Pirates' bullpen, which ranked third in the majors with a 2.99 ERA entering the game, has allowed 13 runs in 132/3 innings in the past four games.
The Pirates led, 2-1, before mounting a five-run inning, which came against Padres starter Edinson Volquez in the fourth.
Clint Barmes got his second hit of the game in the fourth before Volquez walked McDonald for the second time. Travis Snider hit his fourth homer this season and first as a Pirate, extending the lead to 5-1.
Volquez walked Andrew McCutchen before leaving the game after allowing six runs in 31/3 innings. He walked four, the same number as in his previous outing, when he did so in 12/3 innings. He has not walked fewer than three batters in a start since May 12 and led the National League in walks entering the game.
• Game: Padres (Marquis 5-6) vs. Pirates (Burnett 14-3), 7:05 p.m.
• Where: PNC Park.
• TV: Root Sports.