PHILADELPHIA -- No American League pitcher had a better ERA over the past two and a half months than Orioles right-hander Kyle Bradish.

So when it appeared the breakout star had settled in after an uncharacteristically rocky start on Wednesday night, O's manager Brandon Hyde opted to let Bradish try to get through seven innings. As it turned out, he faced one batter too many.

Bradish served up the go-ahead home run to Phillies shortstop Edmundo Sosa with two outs in the bottom of the seventh inning in the Orioles' 6-4 loss at Citizens Bank Park. That ended an outing in which Bradish allowed five runs -- his most since April 25 -- on seven hits and a pair of walks.

Despite their second straight loss, the O's remained 1 1/2 games ahead of the Rays in the AL East thanks to Tampa Bay's loss to Miami.

"It was definitely a letdown," Bradish said. "Tough day to not be your best, trying to win a series against a good team."

It's hard to blame Hyde for trying to get a seventh inning out of Bradish.

Not only had Bradish posted an AL-best 2.32 ERA since May 12, but he had just cruised through the fifth and sixth innings. He retired all six batters on a combined 18 pitches, then made quick work of the first two batters in the seventh. With two outs and nobody on, Bradish jumped ahead of Sosa, only to have the Phillies' No. 9 hitter swat a go-ahead home run -- one that landed in the first row of seats in right field -- on an 0-2 fastball off the plate.

“That’s kind of been a big bugaboo for our pitching staff this year -- executing 0-2,” Hyde said. “Up and away, and Sosa put a good swing on it.”

Bradish managed to retire nine of the final 10 batters he faced despite not having his best stuff.

Bradish started the third inning with a four-pitch walk to center fielder Brandon Marsh. Despite throwing only fastballs, Bradish first missed high, then outside, then low, then inside. He also uncorked a wild pitch and a five-pitch walk in what proved to be a two-run inning.

"I wish I knew," Bradish said of the brief lapse in command. "I probably would have made an adjustment earlier. But yeah, I can't really tell you what happened there. Thankfully, I was able to limit it in that inning."

The Phillies added two more in the fourth, when Bradish allowed three straight hits to start the inning. After a pair of singles to start the frame, J.T. Realmuto drilled a two-run double on a sinker over the heart of the plate.

The inning could have been even worse if not for a heads-up play by shortstop Jorge Mateo. With Realmuto on second and nobody out, Mateo fielded a ball up the middle and made a long throw to third base to nab Realmuto for the first out.

Those troublesome innings erased Adley Rutschman's three-run homer in the third inning that had staked Baltimore to a 3-0 lead. Still, the O's managed to tie the game at 4 in the top of the seventh when James McCann hit a leadoff double and later scored on a two-out single by Austin Hays.

So with the game tied and Bradish having retired seven straight batters and thrown only 74 pitches at that point, the righty trotted back out to the mound. One pitch away from ending the seventh, he threw an 0-2 slider that didn’t dive off the plate as intended. Sosa ripped it foul down the line.

“Slider command wasn't as sharp as it has been in the past,” Bradish said. “Left a few balls up there.”

Pivoting to the fastball, Bradish got it off the plate, but wanted the pitch to be higher than it was.

“When an arm doesn’t have his best stuff on a day, you do pivot from scouting reports,” McCann said. “You figure out a way to get outs. At the end of the day, I thought he did a decent job of getting deep in that game when it could have unraveled.”

Bradish's off night marked just the third time in 19 starts this season that he's allowed more than three runs. The 26-year-old has a 3.29 ERA over 19 starts this season, while racking up 95 strikeouts to just 27 walks over 104 innings.

“He’s been really good his last 10 starts -- just had a rough couple innings in the third and fourth tonight,” Hyde said. “Besides that, he had really good stuff. He’ll bounce back.”