ARLINGTON -- D-backs ace Zac Gallen made his job look easy as he cruised through 28 consecutive scoreless innings over his past four starts. But after that streak ended abruptly Tuesday evening against the Rangers, Gallen had to work harder than usual in a 6-4 loss at Globe Life Field.

Gallen turned in a decent, but relatively undistinguished, outing Tuesday after allowing a leadoff double and a streak-snapping run within the game’s first few minutes. In five total innings, he allowed three runs.

“I was riding a hot hand for a little while,” Gallen said. “Of course, you’re going to have clunkers here and there, but my job is to put up as many zeros as possible and pitch into the sixth, seventh, eighth inning. For me, under my standards, I’m not really pleased with tonight.”

He did bequeath a lead to the bullpen, though, and he pitched deep enough into the game to earn a victory had the Arizona relievers held off the Rangers. On any given night, perhaps a dozen or more Major League starting pitchers would trade their performances for what Gallen called a “clunker.”

“I haven’t given up a run in 28 innings, so yeah, [it was] a little bit of a clunker,” he said. 

“But I think, more so, a clunker mentally. I was just having trouble just locking it in. … I feel like I didn’t have all the pitches at my disposal.”

Gallen allowed seven hits. All but two were singles -- including four in the fifth inning -- and that much traffic on the bases took a toll. With reliever Scott McGough already loose in the bullpen, it was clear by the time Gallen threw his 94th pitch, inducing an inning-ending double play, that it would be his last.

“Obviously, I’m not super-pleased any time I’m not pitching until at least the sixth inning,” Gallen said. “I just had to grind that one out.”

As usual, Gallen painted the corners without going outside the lines, as he didn't walk a batter. He has walked only two in his past 38 ⅔ innings but the Rangers were able to make just enough contact and extend at-bats just enough to force an early departure. It was Gallen’s shortest outing since his only loss, which came on Opening Day.

“It just goes to show you how good he was [during the scoreless-innings streak]," D-backs manager Torey Lovullo said. "When he’s shutting teams down night after night, or outing after outing, it’s pretty impressive because the big leagues has some good hitters -- guys that can do the things we saw the Rangers do today.”

Gallen’s scoreless-innings streak was the longest active streak in the Majors entering Tuesday, but it was over after three batters. Marcus Semien led off with a double, took third on a groundout and scored on Nathaniel Lowe’s single.

Gallen settled in to retire 12 of 13 batters heading into the fifth inning, before four of the next five Rangers singled off him. He got Lowe on a double-play ground ball to preserve a 4-3 lead.

“I think he made some mistakes, and [the Rangers' hitters] kept just chipping away at him,” Lovullo said. “I don’t think they went for the kill shots. I know he was a little bit frustrated after the outing, but he did his job. He gave us five innings. He fought hard and we were winning the game when he left. It’s a little atypical of what he's been doing for us, but he’s human, and that's what happens.”

In the sixth, reliever Scott McGough gave up a two-out single before he served Ezequiel Duran a high, 94 mph fastball that Duran smacked a Statcast-projected 431 feet into the visitors’ bullpen. With an offense that failed to score in the final six innings, the D-backs were done despite some chances late.

“We put together a little rally in the eighth, and then in the ninth inning, I thought things were coming together with the right hitters,” Lovullo said. “It looked like we clipped a couple of balls, and we just barely missed them.”