Cedric Mullins hit a three-run homer and Anthony Santander added a two-run shot while totalling four RBIs for the defending American League East champions.
Burnes (1-0), acquired in a February trade with the Brewers, struck out 11 batters without issuing a walk. Mike Trout's first-inning homer was the only hit allowed by the 29-year-old right-hander.
Starter Patrick Sandoval (0-1) allowed five runs -- three earned -- in 1 2/3 innings for the Angels, who endured a long afternoon as they began the post-Shohei Ohtani era. Sandoval gave up six hits, walked two and struck out two.
Diamondbacks 16, Rockies 1
Lourdes Gurriel Jr. homered and drove in five runs and Arizona set a franchise record with a 14-run inning while rolling over Colorado in the season opener for both teams in Phoenix.
Gurriel hit a two-run homer in the first inning and drove in three runs with a pair of hits in the 14-run third inning. He scored three times for Arizona, which put together an 18-hit attack. The Diamondbacks' third inning also set a modern major league record (since 1900) for the highest-scoring inning on Opening Day. Ketel Marte also had three hits and scored three times and Gabriel Moreno had three RBIs for Arizona, which went 12-for-15 with runners in scoring position. Arizona's Zac Gallen (1-0) allowed one run and three hits over five innings.
Ryan McMahon reached base four times and had two hits for the Rockies, including an RBI double. Kyle Freeland (0-1) was torched for 10 runs and 10 hits in 2 1/3 innings.
Rangers 4, Cubs 3 (10 innings)
Jonah Heim redeemed himself for a mental miscue by delivering a walk-off single in the 10th inning, sending Texas past Chicago in the season opener in Arlington, Texas.
Chicago seized a 3-2 lead in controversial fashion in the ninth inning, as Michael Busch scored from second base on a wild pitch. Replays, however, showed that pinch hitter Miles Mastrobuoni made contact with a pitch by Jose Leclerc, and Busch alertly scampered home after Rangers catcher Heim did not immediately chase after the ball.
Texas' Travis Jankowski belted a pinch-hit homer to lead off the bottom of the ninth. Adolis Garcia launched a solo shot in the sixth inning among his two hits. Cubs ace left-hander Justin Steele exited the game in the fifth due to left hamstring tightness.
Red Sox 6, Mariners 4
Tyler O'Neill set a major league record by hitting a home run on Opening Day for a fifth consecutive season as Boston defeated host Seattle.
A former Mariners draft pick acquired from St. Louis in the offseason, O'Neill broke the record of four set by Yogi Berra (1955-58) and matched by Gary Carter (1977-80) and Todd Hundley (1994-97). Right-hander Brayan Bello (1-0) pitched five solid innings for the Red Sox, allowing two runs on five hits with no walks and two strikeouts. Kenley Jansen pitched the ninth for the save. Boston's Rafael Devers went 2-for-5 with a double and a two-run homer.
Mitch Haniger and Dylan Moore hit two-run shots for the Mariners, who had won their previous three openers and 14 of 17.
Dodgers 7, Cardinals 1
Mookie Betts and Freddie Freeman hit home runs, while Shohei Ohtani and Tyler Glasnow delivered key contributions in their first home game for their new team as Los Angeles beat St. Louis.
After receiving a standing ovation from the Dodger Stadium crowd of 52,667 before his first at-bat, Ohtani reached base in his first three trips to the plate with a pair of hits and a walk. Ohtani signed a 10-year, $700 million heavily deferred contract in the offseason.
Paul Goldschmidt hit a home run for the Cardinals as he continued his career-long success against the Dodgers, but St. Louis' injury woes were too difficult to overcome. Goldschmidt had all three of the Cardinals' hits.
