CLEVELAND -- It was quite the 25th birthday for Mickey Moniak.

Moniak made the most of his Major League season debut on Saturday, going 3-for-4 with a leadoff homer, two stolen bases and a walk, It wasn’t enough in a frustrating 8-6 loss to the Guardians at Progressive Field.

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The Angels led by four in the eighth inning, only for reliever Andrew Wantz to struggle and Ryan Tepera to allow a go-ahead three-run homer by Josh Naylor. It spoiled Moniak’s strong showing, but it was still a season debut to remember.

“It felt good,” Moniak said. “The main focus ever since coming into Spring Training was just trying to help the team win. And, obviously, I felt like I did that today. It’s just baseball that it didn’t fall in our favor, but it felt good to get back here and get my feet wet.”

Moniak made some history in the loss, however, becoming the first player in AL/NL history to make a season debut on their birthday and hit a leadoff homer. Additionally, he became the first player in AL history with at least three hits, three runs and two stolen bases on a birthday.

“Great ballgame for him,” manager Phil Nevin said. “Really happy for him. Birthday. First day back. He's been working his tail off on a lot of things. And it really showed tonight. You can tell on his swing how it's freed himself up.”

Moniak, the No. 1 overall pick in the 2016 MLB Draft, was called up on Friday after excelling at Triple-A Salt Lake, posting a slash line of .308/.355/.585 with eight homers, five triples and 23 RBIs in 33 games. It was a continuation of a strong showing in Spring Training after he worked in the offseason to make a few mechanical tweaks with his swing.

With the Angels facing a slew of right-handed starting pitchers and Nevin wanting to get regular outfielders Mike Trout, Taylor Ward and Hunter Renfroe some rest, Moniak was brought up to provide outfield depth. Moniak started in place of Ward in left field on Saturday and took over Ward’s leadoff spot in the order.

Moniak made an instant impact with a solo blast off Guardians right-hander Cal Quantrill to open the game. Moniak fell behind in the count, 0-2, but connected on a 1-2 curveball for his fifth career homer in 67 games.

“It felt incredible,” Moniak said. “It was good to get the first one out of the way early. It was special. I have a lot of family and friends back home texting me. So it’s cool to see their reaction.”

Moniak sparked a rally in the third with a one-out walk before stealing his second career base. Trout was hit by a pitch before Moniak scored on a double by Shohei Ohtani. Trout eventually scored on a sacrifice fly from Anthony Rendon.

Moniak led off the fifth with a single on a 1-2 changeup at the bottom of the zone, but the Angels failed to score that inning. In the seventh, Moniak again led off the inning with a single on a 1-2 changeup, this one from reliever Enyel De Los Santos. This time, the Angels capitalized, as Moniak stole second base and scored on a two-out RBI single from Luis Rengifo.

“When I got to first base, I just tried to get my reads and time them,” Moniak said. “And I just tried to do everything I could to reach second, and it worked out a couple times tonight.”

The Angels still have high hopes for Moniak, who was acquired at last year’s Trade Deadline from the Phillies in exchange for right-hander Noah Syndergaard. Moniak started out well with the Angels after the trade, hitting .286 with two homers through his first five games, but suffered a broken middle finger on a bunt attempt that kept him out of action for a month. He showed some glimpses down the stretch and made it his mission to improve this offseason.

Moniak worked with hitting coach Marcus Thames and assistant hitting coach Phil Plantier to clean up his mechanics, trying to keep his weight centered and his head still at the plate. He also opened up his stance, which allows him to see the ball better.

“The home run was one thing, but for me the tell was the line drive he had to right-center on the changeup,” Nevin said. “I told Marcus, ‘I know he doesn't make that move last year.’ He’s just done some really nice things with his swing and setup. His posture looked really good.”