Starlin Castro blasted the Chicago Cubs past the St Louis Cardinals with two home runs in an 8-3 win against their division rivals in MLB on Friday.

The win moves the Cubs just six games back in the National League (NL) Central and a game behind the Pittsburgh Pirates, who hold the top wildcard spot.

Castro, who has been moved from shortstop to second base, was a perfect three-for-three with six RBIs and a walk.

The Pirates suffered a 6-2 loss to the NL West-leading Los Angeles Dodgers.

The New York Mets maintained their eight-game buffer atop the NL East after a 5-1 win over the New York Yankees and the Washington Nationals' 5-4 defeat of the Miami Marlins.

The loss hurt the Yankees, who fell four-and-a-half games behind the Toronto Blue Jays in the American League (AL) East.

The Blue Jays were untroubled by the Boston Red Sox in a 6-1 win to open their series.

The Houston Astros, who are in a wildcard spot, went down to the Oakland Athletics 4-3, but the Texas Rangers were unable to capitalise.

The Rangers remain two-and-a-half games clear in the AL West despite their 3-1 loss to the Seattle Mariners.

AL Central leaders the Kansas City Royals suffered a 5-4 walk-off loss to the Detroit Tigers after a Dixon Machado single in the 12th.

Elsewhere, there were wins for the Tampa Bay Rays (8-6 over the Baltimore Orioles), Cleveland Indians (12-1 over the Chicago White Sox), Atlanta Braves (2-1 over the Philadelphia Phillies), Cincinnati Reds (5-3 over the Milwaukee Brewers), Colorado Rockies (7-4 over the San Diego Padres) and Arizona Diamondbacks (2-0 over the San Francisco Giants).

Rain saw the Minnesota Twins-Los Angeles Angels game postponed.

STAR PERFORMERS
AL:
Making just his second start of the season, Blue Jays pitcher Marcus Stroman allowed one run in seven innings with three strikeouts.

Indians shortstop Francisco Lindor went three-for-five with a solo home run — his 10th of the season — which makes him the 22nd rookie to reach that total this season. This season's rookie class is the largest to reach 10-plus home runs in MLB history.

NL:
Mets first baseman Lucas Duda and outfielder Daniel Murphy both went two-for-four with a solo home run in their 5-1 win against the Yankees.

A LOOK AHEAD
The Mets have Noah Syndergaard on the mound against the Yankees, the Cubs look to continue closing in on the Cardinals and Clayton Kershaw's Dodgers host the Pirates.

REACTIONS
"The team is playing pretty good," Castro said, via MLB.com. "I just try to work hard. I try to be here, in my mind, [thinking] I might play that day. Even if I'm not going to start, I think I might get in the game in the seventh or something like that. I just try to keep positive. I don't want to be the negative guy on the team, and try to be positive and keep winning games."