Bryant, who is wearing No. 17, was called up by the Cubs after third baseman Mike Olt went on the disabled list with a hairline fracture in his right wrist after being hit by a pitch last weekend.
"I really can't put into words how good of a feeling this is," Bryant said before the game. "The journey is just starting. This isn't where I want to end. I want to win a lot of games and win for the Cubs. This is a good starting point."
Cubs president of baseball operationsTheo Epstein said Bryant would not have been called up Friday if not for the injury to Olt.
"We like to do it on the road for prominent players that get a lot of attention and have a lot to deal with," Epstein said, "so we would have done it a little bit later, but you can't script everything out in baseball."
Tommy La Stella, another third-base option, is out with a rib cage injury.
According to ESPN Stats & Information, the last time a Cubs player debuted by starting in the cleanup spot was 73 years ago -- Heinz Becker, during World War II.
"I called my mom first because my dad was doing hitting lessons," Bryant said. "She was shocked. My dad was crying. I've never seen my dad cry before."
Bryant was hitting .321 (9-for-28) at Triple-A Iowa after hitting his third home run Thursday night against New Orleans. He hit a fifth-inning pitch to the wall in right that looked like it was going out, but he was robbed after a great catch. An inning later, Bryant went deep in left with a ball that barely stayed fair.
The 23-year-old Bryant was a topic of conversation all spring as he led the Cactus and Grapefruit leagues with nine home runs and had a .477 batting average in 40 at-bats.Last season he was named the minor league player of the year, hitting .325 with 43 home runs and 110 RBIs split between Double-A and Triple-A.
"I said my expectations are that you play hard and enjoy yourself," Cubs manager Joe Maddon said.
Bryant was the No. 2 draft pick out of San Diego in 2013 after leading all collegiate players in home runs with 31.
Months later, Bryant won the MVP of the Arizona Fall League, also leading all hitters in home runs. Then came his breakout season in the minors in 2014.
Bryant became the face of a controversial rule in the collective bargaining agreement that states a player is credited with a full year of service time if he is in the majors for 172 days out of the 183-day season. By keeping a player in the minors for the first 11 days of the season, a team can retain his rights for an extra year before he becomes a free agent.
By recalling Bryant on Friday, the Cubs have control over him until after the 2021 season instead of 2020. The decision to send Bryant to the minors prompted his agent, Scott Boras, to be critical of the Cubs, while the front office said he was going back to the minors for purely baseball-related reasons.
Bryant dismissed the controversy talk Friday.
"I don't think about the past at all," Bryant said. "I'm here now. I'm ready to play some ball."
The past two Cubs to start in their major league debuts, Javier Baez and Jorge Soler, each homered. Bryant can also call upon Starlin Castro for some advice. Castro had a homer and six RBIs in his major league debut in 2010.
Information from ESPN.com's Mike Triplett was used in this report.