ST. LOUIS -- Ian Happ had an eventful and unforgettable Major League debut.
Happ was called out on a slide at second base in the fifth that resulted in an inning-ending double play, didn't get credit for a hit when first baseman Matt Carpenter was charged with an error, and hit a two-run homer in the seventh inning of the Cubs' 5-3 loss to the Cardinals on Saturday at Busch Stadium.
"He was never overwhelmed being here today," manager Joe Maddon said of Happ, the Cubs' No. 1 pick in 2015 who started in right field and batted second. "He walked in, put his uniform on, went out there and kicked the bench and shook hands and hit a homer."
Happ is the first Cubs player to homer in his Major League debut since Jorge Soler did so on Aug. 27, 2014. He thought he had his first big league hit in the fifth, but the official scorer instead charged Carpenter with an error. Cardinals catcher Yadier Molina must have agreed with Happ, because he threw the ball to the Cubs' dugout to save it.
There was no doubt about Happ's home run off the first pitch of his at-bat in the seventh -- and what would be Carlos Martinez's last pitch of the game. Happ launched the ball to right field, much to the delight of his cheering section that included his mother, brother, three cousins, an aunt and a couple of uncles.

Happ watched as young players were promoted last season and contributed to the Cubs' World Series run.
"That's been the M.O. for this team the last two years," Happ said. "If I can do anything I can to help, that's what I want to do."
Happ was able to share the good news in person late Friday night because his mother, uncle and brother were at Triple-A Iowa's game in Salt Lake City. Ranked No. 2 on MLBPipeline.com's list of top 30 Cubs prospects, Happ was needed because of injuries to players, including Addison Russell (right shoulder), Benjamin Zobrist (back), Kristopher Bryant (ill) and Jonathan Jay (back).

"We needed him and he's here. How long is he going to stay? I have no idea," Maddon said. "It could be short, it could be longer than that. I don't know."
Happ was batting .298 at Iowa with nine home runs and 25 RBIs in 26 games. The slugger was on the disabled list for a short time with a bone bruise on his left thumb, but he had come back strong, going 10-for-20 in his last five games. On Friday, he went 3-for-5 with a double and one RBI. It was his second straight three-hit game.
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It was emotional when he told his mother, uncle and brother the news.
"I was able to tell them in person, and tell my mom in person," Happ said. "It was great to be able to tell those people in person."

Happ just hoped he would remember what happened.
"You just have to take it in and enjoy it," he said before the game. "It's one of those situations where I might wake up tomorrow and not remember what happened. You just have to slow everything down and enjoy it and be in the moment."
Happ had an impressive spring, batting .383 in 29 games, and he kept it going at Iowa.
"I felt good about what I did in spring, and being there, being a sponge, picking everybody's brains," Happ said. "I was excited to go to Iowa and compete there, and [am] fortunate to end up here."
"He's made an awesome impression on everybody," Zobrist said. "He's got power, he's patient as a hitter, he's a strong kid and he can hit. I think he's going to help us, and I'm excited for him to help us."