Following a stirring pre-game ceremony, which paid tribute to the victims and emergency services of the Boston Marathon bombings, the hosts were boosted by Daniel Nava's three-run homer which set up a 4-3 success.
Elsewhere, the Cleveland Indians were stunning 19-6 winners over the Astros at Houston - the visitors scored eight runs in the first and kept on going.
LA Angels were also quick out of the blocks to set up a fourth successive win.
Mike Trout smacked his first career grand slam to cap a nine-run first inning which paved the way for a 10-0 success over the Detroit Tigers which wrapped up a series victory.
The Baltimore Orioles won both games of their double-header against the LA Dodgers, following a 7-5 success in the opener with a 6-1 win.
The Atlanta Braves were beaten for the second time in as many nights, going down 3-1 to the Pittsburgh Pirates at PNC Park, while Vernon Wells excelled against his former team as the New York Yankees sunk the Toronto Blue Jays 5-3.
Brandon Phillips hit a sacrifice fly to center field off Steve Cishek to score Shin-Soo Choo and give the Cincinnati Reds a 3-2, 13-inning win over the Miami Marlins at Great American Ball Park.
Ryan Doumit raced home with the winning run following Alexei Ramirez's throwing error in the 10th inning as the Minnesota Twins recorded a 2-1 victory over the Chicago White Sox.
Bryce Harper belted a two-run homer in the third inning and a go-ahead blast in the eighth to carry the Washington Nationals past the New York Mets, 7-6.
St Louis Cardinals' Lance Lynn allowed only one hit and struck out eight Philadelphia Phillies in seven dominant innings as the visitors won 5-0 at Citizens Bank Park.
Debutant Hiram Burgos allowed only one run on five well-placed hits in five innings as the Milwaukee Brewers brushed aside the Chicago Cubs 5-1 at Miller Park.
Matt Joyce's solo homer was enough to give the Tampa Bay Rays a 1-0 win over the Oakland Athletics, while AJ Pierzynski and David Murphy homered in the Texas Rangers' 5-0 win over the Seattle Mariners.
The Colorado Rockies stretched their winning run to eight with a 4-3 defeat of the Arizona Diamondbacks, while Pablo Sandoval's two-run homer helped the San Francisco Giants top the San Diego Padres 2-0 at AT&T Park.