The Los Angeles Dodgers set a record for home runs on the opening day of a Major League Baseball season with eight in the 12-5 victory over the Arizona Diamondbacks.
Joc Pederson and Enrique Hernandez each hit two at Dodger Stadium, with Austin Barnes, Corey Seager, Max Muncy and Cody Bellinger also in on the action.
The eight home runs equalled the Dodgers' own record in any game as their pursuit of a third successive National League pennant started in style.
World Series champions the Boston Red Sox began with defeat after they went down 12-4 to the Seattle Mariners.
Tim Beckham hit two of Seattle's three home runs off Red Sox pitcher Chris Sale.
At Petco Park, the San Francisco Giants were beaten 2-0 by the San Diego Padres.
Despite the win, Manny Machado went hitless in his first game for the Padres after signing a lucrative 10-year contract in February.
The New York Yankees started the campaign with a 7-2 win over the Baltimore Orioles.
Home runs from Luke Voit and Greg Bird helped the hosts to victory at Yankee Stadium.
In Arlington, Chris Woodward endured a difficult start as Texas Rangers manager following a 12-4 loss to the Chicago Cubs.
Javier Baez hit two home runs for the Cubs, who are on the back of four play-off appearances in a row under Joe Maddon, including the 2016 World Series title.
The Milwaukee Brewers secured a dramatic 5-4 success over the St Louis Cardinals after centre fielder Lorenzo Cain denied Jose Martinez a tying home run in the final action of the game.
Elsewhere, the Houston Astros defeated the Tampa Bay Rays 5-1 at Tropicana Field, the Minnesota Twins overcame the Cleveland Indians 2-0, and the Cincinnati Reds gave new manager David Bell a winning start by beating the Pittsburgh Pirates 5-3.
The Philadelphia Phillies won 10-4 against the Atlanta Braves, while the Kansas Royals beat the Chicago White Sox 5-3 after the start of their match was delayed nearly two hours by rain.
In Thursday's other matches, the New York Mets won 2-0 at the Washington Nationals, the Oakland Athletics beat the Los Angeles Angels 4-0, the Detroit Tigers defeated the Toronto Blue Jays 2-0, and the Colorado Rockies saw off the Miami Marlins 6-3.