For Strasburg, this marked the start of what should be his first full season in the majors, with zero pitch or inning limits. The All-Star ace was dominant against a trade-depleted Marlins lineup that features Giancarlo Stanton and little else. The right-hander went seven innings, matching his career high, and allowed three hits.
Reigning NL Rookie of the Year Harper, a 20-year-old outfielder, hit solo shots over the out-of-town scoreboard in right-centre field off Ricky Nolasco in the first and fourth innings.
New closer Rafael Soriano got the save.
DODGERS 4, GIANTS 0
LOS ANGELES (AP) — Clayton Kershaw launched his first career home run to break a scoreless tie in the eighth inning, then finished off a four-hitter that led the Los Angeles Dodgers past the San Francisco Giants.
Kershaw became the first pitcher to throw a shutout and hit a home run in an opener since Bob Lemon for Cleveland in 1953, STATS said.
Kershaw struck out seven, walked none and retired World Series MVP Pablo Sandoval on a grounder to end it.
Matt Cain made his first career opening day start for the Giants in the loss. He allowed four hits in six scoreless innings, struck out eight and walked one.
METS 11, PADRES 2
NEW YORK (AP) — Jonathon Niese stepped nicely into his new role as No. 1 starter for the Mets, and Collin Cowgill capped a successful New York debut with a grand slam in a rout of the San Diego Padres.
Handed the opening day assignment in place of injured Johan Santana, Niese enjoyed a big afternoon with both his arm and bat. He breezed into the seventh inning against a Padres lineup missing slugger Chase Headley (broken thumb) and catcher Yasmani Grandal, suspended for the first 50 games after testing positive for testosterone.
Marlon Byrd had a pair of RBI singles and fellow Mets newcomer John Buck was in the middle of three rallies as New York improved baseball's best opening day record to 34-18 despite dropping its first eight openers.
CUBS 3, PIRATES 1
PITTSBURGH (AP) — Jeff Samardzija struck out nine in eight nearly flawless innings and the Chicago Cubs held on for a victory over the Pittsburgh Pirates.
The right-hander allowed just two hits and walked one as the Chicago won on opening day for the first time since 2009. Anthony Rizzo hit a two-run homer and Wellington Castillo added an RBI double for the Cubs.
Kyuji Fujikawa got a save in his major league debut after closer Carlos Marmol struggled.
A.J. Burnett, making the first opening day start of his lengthy career, gave up three runs on six hits in 5 2-3 innings, striking out 10.
BREWERS 5, ROCKIES 4, 10 innings
MILWAUKEE (AP) — Jonathan Lucroy hit a sacrifice fly in the 10th inning to give the Milwaukee Brewers a victory over Colorado, ruining the first game for new Rockies manager Walt Weiss.
Rickie Weeks sparked the winning rally when he stole second after he was hit by a pitch with one out. Adam Ottavino then issued an intentional walk to Ryan Braun and lost Aramis Ramirez to another walk before Lucroy ended the game with a fly ball to centre field.
A big "Luuuuuuc" thundered down from the Miller Park crowd of 45,781 as Weeks came home with the winning run and Lucroy was mobbed by his jubilant teammates.
Ramirez also had a two-run double in Milwaukee's three-run eighth inning as the Brewers won on opening day for the first time since 2008.
BRAVES 7, PHILLIES 5
ATLANTA (AP) — Freddie Freeman drove in three runs with three hits, including the first of three Atlanta home runs, and the Braves beat Cole Hamels and the Philadelphia Phillies.
Dan Uggla and Justin Upton, making his Braves debut, also homered for Atlanta, which led National League teams with 49 in spring training.
Hamels (0-1) struggled in his first opening day start. He gave up five runs on seven hits, including the three homers, with five strikeouts and one walk in five innings. The three homers allowed matched his high from last season.
DIAMONDBACKS 6, CARDINALS 2
PHOENIX (AP) — Ian Kennedy struck out eight in seven strong innings and the Arizona Diamondbacks used 15 hits to beat the St. Louis Cardinals.
Kennedy (1-0) allowed two runs on five hits with one walk. St. Louis' Adam Wainwright (0-1) went six innings, giving up four runs, three earned, on 11 hits. He struck out six with no walks.
Arizona's Gerardo Parra matched his career best with four hits, three of them doubles. Rookie A.J. Pollock was 3 for 4, including a two-run double, and Martin Prado doubled twice with an RBI and two runs scored for the Diamondbacks.
ANGELS 3, REDS 1, 13 innings
CINCINNATI (AP) — Chris Iannetta hit a solo homer early in the game and a bases-loaded single in the 13th inning, powering the Los Angeles Angels past the Cincinnati Reds in the majors' first interleague season opener.
The Angels loaded the bases with two outs in the 13th off J.J. Hoover, who walked two and hit Hank Conger, the Angels' final position player. Iannetta worked the count full, fouled off a pair of pitches, then singled to left. Ernesto Frieri, the Angels' seventh pitcher, finished off the Reds' longest opening game since 1975, when they beat the Dodgers 2-1 in 14 innings.