The Atlanta Braves won their fourth game in a row to maintain their advantage at the top of the National League East.

A first career grand slam by David Ross was instrumental in the Braves beating the New York Mets 9-2 on Tuesday.

The Philadelphia Phillies remain three games behind after an 8-4 win at the Los Angeles Dodgers and the Florida Marlins snuck past the Washington Nationals 1-0 after an extra inning.

The Cincinnati Reds extended their lead in the NL Central to seven games thanks to an 8-4 success at home to the Milwaukee Brewers coupled with a 3-0 defeat for the St Louis Cardinals at the Houston Astros.

Pitcher Wandy Rodriguez limited the Cardinals to two hits in seven scoreless innings and in the process helped his team to their eighth win in 10 games.

In the other game in the Central on Tuesday the Pittsburgh Pirates won 14-7 at the Chicago Cubs but still remain the team with the fewest wins (44) in the whole of Major League Baseball this season.

NL West leaders the San Diego Padres suffered a sixth defeat in a row as they lost 7-4 at the Arizona Diamondbacks, for whom Ian Kennedy struck out five over seven innings.

The San Francisco Giants moved within four games of the Padres as Madison Bumgarner's first career double helped them to a 5-2 home win over the Colorado Rockies.

In the American League East, the New York Yankees edged back in front of the Tampa Bay Rays courtesy of a 9-3 success at home to the Oakland Athletics.

Mark Teixeira, Nick Swisher and Curtis Granderson all contributed home runs to the Yankees' cause, while the Rays slipped up at the Toronto Blue Jays, losing 13-5 and conceding 10 runs in the sixth inning alone including Jose Bautista's 43rd homer of the season.

The AL East's bottom team, the Baltimore Orioles, continued their recent improvement, beating the Boston Red Sox 5-2 to seal a fourth victory in a row.

The Minnesota Twins maintained their four-game advantage over the Chicago White Sox in the AL Central by virtue of a 4-3 home win against the Detroit Tigers secured by Delmon Young's go-ahead hit in the seventh inning.

The White Sox proved too strong for the Cleveland Indians as 11 strikeouts from Edwin Jackson and an AJ Pierzynski homer in the ninth steered them to a 4-3 victory.

AL West leaders the Texas Rangers were edged out 10-9 at the Kansas City Royals while the Seattle Mariners were 3-1 victors at home to the Los Angeles Angels.