The Cubs beat the Marlins in Miami 8-4 on Opening Day. The White Sox also won their Opening Day game against the Kansas City Royals, trouncing them 14-7.
Ian Happ of the Chicago Cubs hit a home run on the very first pitch of the year, connecting Thursday against Miami's Jose Urena at Marlins Park.
Happ tagged a 95 mph fastball and sent it far over the right field fence.
The drive kept up a familiar pattern in the majors: big leaguers hit a record 6,105 home runs last season.
Happ's homer was part of a three-run first inning for the Cubs. New Marlins CEO Derek Jeter watched his team instantly fall behind from his seat two rows back of the Miami dugout.
Matt Davidson became the fourth player in major league history to homer three times on opening day, the White Sox went deep six times total and Chicago routed the Kansas City Royals 14-7 on Thursday to spoil their 50th anniversary celebration.
Tim Anderson also homered twice and Jose Abreu went deep for the White Sox, who picked up James Shields (1-0) in a big way after the former Royals ace surrendered four runs in the first inning.
Shields wound up lasting six innings, holding Kansas City without a hit after that shaky first.
Of the four players with three-homer opening days, three have done it against the Royals, while the six homers by Chicago on opening day matched the big league record set by the Mets in 1988.
Yolmer Sanchez added a three-run single and Yoan Moncada drove in a pair of runs for the White Sox, who forced Royals manager Ned Yost to burn through nine pitchers.
Danny Duffy (0-1) breezed through three innings for Kansas City, but a trio of homers in a five-run fourth turned his day around. The left-hander survived the inning before hitting the clubhouse.
Despite a cold rain and steel-gray skies, the Royals looked early on as if they would reward the hardy fans who turned out to celebrate the start of their golden anniversary season.
Longtime third baseman Mike Moustakas, who signed a one-year deal during spring training, provided an RBI single in the first before new first baseman Lucas Duda hit a three-run homer to right.
Everything unraveled when the fourth inning began.
Abreu led off a homer binge with a two-run shot, Davidson followed with his first home run, and Anderson added his first two batters later. By the time Moncada added an RBI double off Duffy later in the fourth inning, Chicago had turned a four-run hole into a 5-4 advantage.
Davidson and Anderson went deep again in the fifth off Royals reliever Blaine Boyer, and Sanchez tacked on a bases-clearing single off Burch Smith with two outs in the seventh.
Davidson capped his big game with a three-run homer off Brian Flynn in the eighth, becoming the first White Sox player with a three-homer game since Dan Johnson in October 2012.
The Chicago Cubs and White Sox announced their lineups for Opening Day earlier Thursday.
Center fielder Ian Happ was the lead-off man for the Cubs, followed by third baseman Kris Bryant, first baseman Anthony Rizzo, catcher Willson Contreras, left fielder Kyle Schwarber, shortstop Addison Russell, right fielder Jason Heyward, second baseman Javy Baez and pitcher Jon Lester.
The Chicago White Sox are in Kansas City to play the Royals at 3:15 p.m.
Second baseman Yoan Moncada will bat leadoff for the Sox, followed by right fielder Avisail Garcia, first baseman Jose Abreu, designated hitter Matt Davidson, left fielder Nicky Delmonico, catcher Welington Castillo, shortstop Tim Anderson, third baseman Yolmer Sanchez and center fielder Adam Engel. James Shields will take the mound as the Sox starting pitcher.
The March 29 start date is the earliest in the history of Major League Baseball, not including international openers. It is also the first time all teams are scheduled to play on Opening Day since 1968. However, Cincinnati did postpone because of rain.
The Cubs Home Opener takes place on April 9, and you can watch that on ABC7.
The Associated Press contributed to this report.