By the time Pirates starter Trevor Cahill escaped the first inning against the Brewers on Saturday, the game already seemed out of reach.

Cahill allowed five runs on six singles in the first inning, five coming with two outs after Brewers center fielder Jackie Bradley Jr.’s leadoff base hit. Milwaukee scored two more runs in the second, and even though Cahill settled down to get back-to-back 1-2-3 innings in the third and fourth, that early deficit was enough to sink Pittsburgh in the 7-1 loss at American Family Field.

• Box score

“In the first inning he gave up a couple bloop hits and had two balls go down the line. Didn't run into a lot of luck early on,” Pirates manager Derek Shelton said. “A couple balls fell in, a couple balls got hit in the right spot and it was able to extend innings, and they did a nice job continuing to put the ball in play.”

Cahill’s rough first inning added to a list of futile first-inning performances for the Pirates’ staff.

Through 15 games, Pittsburgh has allowed 23 total runs in the opening frame -- the worst mark in the Majors -- and opponents have scored at least once in the first inning in 10 games. The staff holds a 12.60 ERA in the first, and if not for JT Brubaker throwing a scoreless first in each of his three starts, that number would balloon to 15.75.

“It makes it tough when I feel like every single outing the leadoff guy seems to reach base and you're [pitching] out of the stretch right away and you're into some trouble. So it makes it tough and just kind of takes a lot out of you,” Cahill said. “[It’d] be nice to have a clean inning.”

Cahill’s final box score doesn’t look good, but some luck on the Brewers’ side in that first inning did play a part.

Each of Milwaukee’s six singles -- six of the eight total hits off Cahill -- came in the frame. Of the six, four registered exit velocities of 87.1 mph or less according to Statcast, but they all went for base hits to extend the long inning.

Bradley led off with a ground-ball base hit, and after Cahill retired the next two batters, Brewers right fielder Avisaíl García blooped a single that left the bat at just 72.2 mph into center to score Bradley. Milwaukee catcher Omar Narváez, left fielder Billy McKinney, shortstop Luis Urías and second baseman Jace Peterson all followed with singles -- two of them on grounders -- to put another four runs on the board.

It was a night the Brewers could do no wrong early on, as they hit plenty of perfectly placed balls that put the Pirates in a bind right out of the gate.

“I think that's the case, and because of that, Trevor's line looks worse than how he pitched, personally,” Shelton said.

“When you're out there, it doesn't really matter,” Cahill said. “They could've all been solo homers. I don't know. It's just a hit, and you're trying to compete and just not let them reach base. I try and execute a pitch and whatever happens is kind of like the result of that, and the results weren't good.”

Pirates left fielder Bryan Reynolds and second baseman Adam Frazier combined to go 4-for-8 and the bullpen pitched four shutout innings to provide some bright spots. But by the time Reynolds scored the club’s lone run in the fourth inning, Pittsburgh was already in a hole it never made its way out of.

“It's just tough when you're a couple pitches in and you go from the windup to the stretch every time,” Cahill said. “I think the biggest thing for me is just being able to put guys away, and just willing your way to get outs.

“That's kind of what the big leagues is. You don't have it, you’ve got to just find a way.”