HOUSTON -- It didn¡¯t take long for Yordan Alvarez to make his mark in the big leagues.

Alvarez, the team¡¯s No. 3 prospect according to MLB Pipeline, who was called up prior to Sunday¡¯s game, hit an impressive two-run homer in his second Major League at-bat in the fourth inning for the Astros, who beat the Orioles, 4-0, in the series finale at Minute Maid Park.

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¡°That first at-bat, obviously, I felt a little bit nervous, but I¡¯ve been thinking about all the players here and how much advice they¡¯ve given me and made me feel comfortable and I felt great in the game,¡± said Alvarez after hitting .343 with 23 homers and 71 RBIs in 56 games at Triple-A Round Rock.

Orioles starter Dylan Bundy didn¡¯t allow a hit until Yuli Gurriel singled with two outs in the fourth, and two pitches later, Alvarez clobbered a 413-foot homer to left-center field to put Houston ahead, 2-0. The ball jumped off Alvarez¡¯s bat at 107.3 mph and never got more than 80 feet off the ground.

¡°I saw him take a four-seam heater up and in, and then look for a changeup and get it and homer,¡± Astros third baseman Alex Bregman said. ¡°Really impressive. Really, really impressive.¡±

Alvarez, 21, is the seventh Astros player to homer in his Major League debut and first since Derek Fisher two years ago. He went 1-for-3 and drew a walk in four plate appearances.

¡°I don¡¯t know how many people were in the stadium today, but they all can take credit for probably saying, ¡®Hey, he¡¯s going to homer.¡¯ And he delivers,¡± Astros manager AJ Hinch said. ¡°That¡¯s an incredible performance today when all anybody wanted was a homer from him, and he did it.¡±

Astros starter Wade Miley, who threw six innings against his former club, joined four relievers in dealing a six-hit shutout of the Orioles. The Astros improved to 45-22 -- matching their best record through 67 games in franchise history -- and are 24-7 in their last 31 games.

But this day was about Alvarez.

"That¡¯s a big dude with some long arms who has some serious power,¡± Orioles manager Brandon Hyde said. ¡°I didn¡¯t think it was a terrible pitch, but he got beat with it."

Alvarez, batting fifth and in the lineup at designated hitter, softly flied out to left field in his first big league at-bat in the second inning before his impressive swing in the fourth. He flied out in the sixth and walked in the eighth.

¡°He hits the ball as hard as anybody,¡± Hinch said. ¡°I said that pregame, and it was well-timed, obviously. We needed it. We needed that presence, we needed that production and what a first day for him.¡±

Alvarez, an imposing 6-foot-5 presence in the box, will get most of his at-bats at DH, but he will have to play some left field as well. Hinch uses the DH to rotate some of his regular players through for rest, mainly outfielders Michael Brantley and George Springer. Hinch said Alvarez won¡¯t play first base with Houston.

Alvarez was acquired by Houston in exchange for relief pitcher Josh Fields in August 2016. The Dodgers gave Alvarez a $2 million signing bonus after signing him out of Cuba in June 2016, and then sent him to Houston two months later.

¡°This is a long road to get him here,¡± Hinch said. ¡°From [senior scouting advisor] Charlie Gonzalez advocating for him when he was an amateur and [president of baseball operations and general manager] Jeff [Luhnow] making the trade, and then to get him through the Minors and get him up here, a lot of people were watching and a lot of people should take satisfaction in the win today with his performance.¡±