"It's been fun," Upton said. "We've won some ballgames, and I've hit the ball well. It's just been a good first month."
The Braves acquired Upton in a trade with the D-backs in January. The team signed his brother, B.J., to a five-year contract earlier in the offseason. The revamped outfield helped Atlanta to a 17-9 April record, best in the NL.
"It's been a pretty smooth transition for me," Justin said. "I've enjoyed the new team and the new surroundings. It's a great group of guys."
Upton's 12 long balls in April fell two short of the modern record of 14, set by Albert Pujols in 2006 and Alex Rodriguez in '07. The 25-year-old became the 18th player in MLB history to slug 10 homers prior to his team's 20th game. He surpassed the franchise record of 10 homers in April, previously held by Andres Galarraga and Ryan Klesko.
Last season, Upton hit 17 home runs in 150 contests. A change of scenery seems to have served him well. Upton hit five homers in his first five games in a Braves uniform, becoming the first player in MLB history to do so for a new team.
"You always want to get off to a hot start," he said. "Sometimes it doesn't work out and it's an uphill battle. Once you can find a groove early, it allows you to keep what you've got and just try to fine-tune everything else."
Upton claimed his second career monthly award despite impressive opening months from a slew of NL stars. Washington's Bryce Harper batted .344 with nine homers, Cincinnati's Shin-Soo Choo compiled a .477 on-base percentage, Mets catcher John Buck tallied 25 RBIs, and Colorado's Wilin Rosario batted .350 with seven homers.
Zack Meisel is a reporter for MLB.com. Follow him on Twitter @zackmeisel. This story was not subject to the approval of Major League Baseball or its clubs.