ANAHEIM -- With the Angels desperate to avoid extra innings yet again after Thursday’s 16-inning marathon drained their pitching staff, rookie Matt Thaiss came to the rescue with a walk-off solo homer in the ninth inning to lift them to a 5-4 win over the Orioles to avoid a four-game sweep on Sunday afternoon at Angel Stadium.

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Thaiss recorded his first multihomer game as a result, as he also smacked a two-run blast in the second. But it was his second homer that proved to be the much-needed winner, helping the Halos hold onto their American League Wild Card hopes with Wednesday’s 1 p.m. PT Trade Deadline looming. They remain five games back of the A’s for the second AL Wild Card spot, with the Red Sox and Rays also between them and Oakland.

“We needed a win and a walk-off definitely helps,” Angels manager Brad Ausmus said. “We could barely afford to go a few more innings. Our relievers are about as taxed as they’re going to get at any point in a season. So it ended up being a huge home run, not because it’s a walk-off win, but because it saved our pitchers having to throw another inning or two.”

Thaiss, ranked as the club’s No. 6 prospect by MLB Pipeline, came to the plate with one out in the ninth and the game tied with O's closer Mychael Givens on the mound. Thaiss fell behind in the count 0-2, but he worked the count full before crushing a 95.4-mph fastball to right-center field to give the Halos the dramatic win.

“I think I got jumpy the first pitch there,” Thaiss said. “I had to go to a two-strike approach and kind of battle. I think I also missed a couple pitches early in the at-bat. I got to 3-2 and got a good pitch to hit.”

Thaiss’ first homer came on a two-run shot off Dylan Bundy in the second on an 0-2 slider that the right-hander left up in the zone. Thaiss now has four homers in 12 career games, including three over his last three games after also homering on Friday. Thaiss hit .333 with three homers and five RBIs in the four-game set.

“I think [when] he first got here, he was a little excited and wide-eyed,” Ausmus said. “He got away from what he was doing well in the Minors, which was get the ball in the zone and attack it where he can hit it. He was kind of chasing. I’d say the last week and a half, the last two weeks, he’s really tightened that up.”

Ausmus has watched Thaiss’ swing evolve, as he worked hard last year with hitting coaches Jeremy Reed, Shawn Wooten and Paul Sorrento to retool his swing path. Thaiss has been able to unlock more power as a result, as that was one of the issues holding him back from reaching the Majors. He’s also improved his versatility, learning to play third base this year in addition to his ability to play first.

“Where his swing was set up a little over a year ago, I think the hitting coaches felt like that would’ve been difficult at the Major League level to create consistent contact,” Ausmus said. “It was actually quite a dramatic change that he made. I’ll give him a credit. It really paid dividends quickly.”

Thaiss, 24, credited the coaches for helping him, but it's still a work in progress. He has shown power, but he is hitting just .189/.268/.541 with 15 strikeouts and four walks through his first 12 games.

"It was a long process," Thaiss said of his overhaul. "A lot of swings, a lot of blisters. I can’t thank those guys enough for what they did and how they helped me, and the time they put in. Nobody really sees that, but they put in a lot of time. I don’t know if I would’ve gotten that pitch three years ago. It’s just a testament to these guys, how much they know and how much they work."