ARLINGTON -- Brandon Pfaadt, the D-backs’ top pitching prospect, got punished by the Rangers almost every time he mislocated a pitch in his Major League debut Wednesday. And he missed a few too many times as the Rangers jolted him for four home runs, two doubles and seven earned runs in 4 ⅔ innings.

Even though Pfaadt got roughed up in his premiere performance, the D-backs ultimately won a 12-7 slugfest at Globe Life Field on Wednesday. The D-backs landed the last blow with a five-run seventh inning as the teams eventually combined for eight homers and 22 hits.

Mistakes aside, it was a special day for the 24-year-old righty Pfaadt, who had some 30 friends and family members cheering for him in section 106.

“It was an awesome day -- a lot of anxiety going up to it, but once I got in the moment, I kind of settled in and got to work,” Pfaadt said. “I’d say after the first [inning], I felt like I was kind of in a groove. And then the fifth came along and I left a few pitches up. But overall, I felt good.”

Pfaadt, who rocketed through every level of the Minor Leagues in just three seasons, derailed in the fifth inning but otherwise turned in a perfectly respectable debut. Early on, despite giving up plenty of hard contact, Pfaadt scattered what little damage he suffered.

Until the fateful fifth frame, the only runs he’d allowed were on solo homers by Jonah Heim and Josh Jung. But the fifth went wrong when Pfaadt gave up a leadoff homer, two doubles, a single, a sacrifice fly and Jung’s second homer, a two-run shot that made the score 7-6.

D-backs manager Torey Lovullo was hoping Pfaadt could get that last out and earn a victory in his first Major League game, but Jung's homer was the end of the rookie's day.

“He deserved the opportunity, based on how he was pitching, to go out and get that win,” Lovullo said. “At the end of it, it’s a two-run home run and there goes the lead -- you’re obviously second-guessing yourself, but it worked out well. I thought he threw the ball well enough.”

Pfaadt was so dominant in the Minors that the D-backs felt compelled to promote him after a total of 15 Triple-A starts in which he posted a 3.00 ERA and 104 strikeouts with only 20 walks. He fanned nearly a third of the batters he faced (104-of-347) with Triple-A Reno over the past two years. He struck out three Rangers on Wednesday.

Offensively, D-backs first baseman Christian Walker led the way with a 2-for-4, five-RBI, two-run day. His two homers were integral to the victory, but his seventh-inning, bases-loaded walk actually plated what ended up being the winning run.

Walker now has four home runs in the past four games. But his patience in drawing that four-pitch walk was almost as impactful as any dinger he’s hit in recent memory. Rangers reliever José Leclerc -- the second of three Rangers relievers that inning -- missed low on the first pitch and high on the next three.

“I’m proud of myself there for some discipline,” Walker said. “It’s easy to go up there and want to launch something, or try to. … [But] in my head there, I was going to take until I got a strike.”

That walk gave the D-backs the lead, but they tacked on three more runs in the inning and finished the Rangers off.

“It was just one thing after another -- good approaches, that’s really what it was,” Lovullo said. “We didn’t give their pitchers too much credit, we were expanding the zone and changing our sight lines a little bit, and counter-punching some quality pitches.

"We impacted the ball when we needed to, but it was us being patient, drawing walks and just having baserunners on base and just continuing to put pressure on the pitcher -- I think we eventually broke them.”