After a shaky first inning, Orioles pitchers blitzed through Friday’s next seven frames. Then came the ninth.

Byron Buxton’s walk-off, two-run home run off Baltimore closer Jorge López gave the Minnesota Twins a 3-2 victory to open their series with the Orioles. Baltimore had been 29-0 when leading after eight innings.

Luis Arraez opened the ninth with a single after a nine-pitch at-bat and Buxton followed with the walk-off blast.

McKenna’s big game

An injury to the hand of one of the Orioles’ core offensive pieces created an opportunity for McKenna. He showed off his arm, glove and legs.

With Trey Mancini continuing to nurse a right hand injury first suffered more than two weeks ago, McKenna drew the start in left field and ended a long bottom of the first by throwing a runner out at the plate. The Orioles’ pitchers followed that throw by retiring the next 21, with McKenna contributing a diving catch to that effort. He began the eighth with a double, eventually scoring the go-ahead run.

It’s been a second straight year of sporadic major league starts for McKenna, a 25-year-old who once ranked among Baltimore’s top prospects. His speed and defensive ability make him an ideal fourth outfielder, but he entered Friday with a .597 OPS while striking out in nearly 40% of his plate appearances, including each of his four in his most recent start Saturday. Still, with Mancini’s absence, Orioles manager Brandon Hyde gave Anthony Santander a night at designated hitter and put McKenna in the field.

Hyde was unable to watch McKenna’s dive or game-winning run from the dugout; Baltimore’s manager was ejected in the third inning, after the Orioles (35-43) scored their first run on Cedric Mullins’ RBI double.

But he was there for McKenna’s first-inning throw, which helped Spenser Watkins escape a lengthy frame with only one run allowed. It was McKenna’s fourth outfield assist, making him the third Oriole with that many; no other American League team entered Friday with multiple outfielders with at least four assists.

After working five scoreless innings in his return to the Orioles’ rotation last week, Watkins bookended the one-run first with another five shutout frames, retiring the final 15 Twins he faced. McKenna’s diving catch to begin the sixth was the 13th of those outs. Cionel Pérez extended the streak to 18, then McKenna opened the eighth with a double.

Mancini said before the game he would be available to pinch-hit in a big spot, and he indeed was, working a long at-bat that ended in a grounder to second that advanced McKenna to third. With Minnesota playing the infield in, McKenna dashed home on Jorge Mateo’s grounder to second base, but Jorge Polanco’s wild throw allowed him to score easily and give Baltimore a 2-1 lead.

Pérez and Félix Bautista combined for a clean eighth before López lost the game in the ninth.

Mancini sits with nagging hand injury

Mancini was out of Tuesday’s lineup after he recently received a cortisone injection in his right hand for a bone growth known as a carpal boss.

Mancini missed three games last month after taking a pitch to the hand on a swing attempt in Toronto. Before Friday’s pinch-hit appearance, he had hits in nine of 10 games since returning, including each of the past eight, with six of his 10 hits going for extra bases. Now hitting .222 in that span, Mancini said before the game he planned to be in Saturday’s lineup.

“It’s nothing that I think about when I’m up at the plate,” Mancini said. “But it’s kind of got to the point where it wasn’t getting too much better. It’s been more of an annoyance than anything. Maybe I’m cutting off my swing maybe a tiny bit because of it, I think, but again, I’d say I’m sacrificing today just to hopefully from here on out not have it be an issue any longer.”

Mancini said he was unsure whether the pitch caused the growth or simply aggravated something that already existed. He also took a pitch to his left hand Saturday in Chicago, though that hand has no issues, he said.

“I give him a lot of credit for trying to grind through,” Hyde said pregame. “He got hit in both hands and in a short amount of time. You need your hands, and when your hands aren’t feeling good, it’s hard to hit so give him credit for trying to post.”

Around the horn

>> Infielder Ramón Urías, on the injured list with a left oblique strain, is expected to begin a rehab assignment with Double-A Bowie as soon as Saturday.

>> Right-hander Kyle Bradish, out with right shoulder inflammation, threw a flat-ground session Friday and is expected to throw a bullpen in the coming days.

>> The first phase of fan voting for starters in this month’s MLB All-Star Game at Dodger Stadium in Los Angeles ended Thursday. Mancini finished eighth among American League designated hitters, while Urías was 10th among AL third basemen. No other Orioles infielders finished among the top 10 at their position, while no Baltimore outfielders were among that group’s top 20 vote recipients. The top six outfielders and two at all other positions advanced as finalists.

>> Infielder Coby Mayo, the Orioles’ No. 5 prospect according to Baseball America, exited Double-A Bowie’s game with back spasms, according to a source with knowledge of the injury, which MASNSports.com first reported.

Baltimore Sun reporter Andy Kostka contributed to this report.

ORIOLES@TWINS

Saturday, 2:10 p.m.

TV: MASN2

Radio: 97.9 FM, 101.5 FM, 1090 AM

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