New York, New York: 1 lead shrinks, 1 grows

Labor Day signaled the four-week mark until the end of the regular season, placing added importance on each game for contenders moving forward.

With a full slate of games Monday, here's a look at some key developments that helped shape the playoff picture:

Mets rally past Nationals
David Wright drove in the go-ahead run as the Mets rallied with three runs in the seventh inning to beat the Nationals, 8-5, in the opener of a critical three-game series in Washington.

Video: NYM@WSH: Wright lines a go-ahead single into left

The victory pushed the Mets' lead over the second-place Nats in the National League East to five games.

"We know it's a big series for us," Wright said. "We knew we had to bring it today. It was an exciting game, an emotional game. The fans get into it, the emotion, the energy. That's what you dream about."

Video: NYM@WSH: Statcast™ tracks Wright's baserunnning

Yankees tighten gap with Blue Jays
The American League East race is shaping up to be a captivating storyline, and the Yankees pulled back to within a half-game of the Blue Jays on Monday.

Video: BAL@NYY: Bird hits three-run shot to put Yanks ahead

The Yankees beat the Orioles, 8-6, behind home runs from Alex Rodriguez, John Ryan Murphy and Greg Bird, while the Blue Jays fell to the Red Sox, 11-4, at Fenway Park.

The race for the AL East crown is sure to heat up later this week, as the Blue Jays will travel to Yankee Stadium for a pivotal four-game series that begins on Thursday night.

The Yankees' win on Monday also maintained their five-game lead over the Rangers for the AL's top Wild Card spot.

Cubs gain ground in division
The Cubs keep moving closer to their first postseason appearance since 2008, and they don't seem content to settle for an NL Wild Card berth.

Video: CHC@STL: Cubs power five runs in the 3rd inning

With Monday's 9-0 win over the Cardinals, the Cubs moved to within 7 1/2 games of St. Louis in the NL Central and two games behind the Pirates for the top NL Wild Card spot. Pittsburgh fell to Cincinnati, 3-1, on Monday.

A playoff bid is very much in play for the Cubs, who lead the Nationals by 8 1/2 games for the second Wild Card. But Joe Maddon's club has its sights set higher.

"I don't see guys settling for a second Wild Card," said Cubs starting pitcher Dan Haren. "I see a push for more."

Other things to know
• The Rangers blanked the Mariners, 3-0, to move within two games of the AL West-leading Astros, who took a 10-9 loss at Oakland. Texas holds a 1 1/2-game lead for the second AL Wild Card spot over the Twins, who kept pace with a 6-2 win over the Royals.

Video: TEX@SEA: Gallardo picks up win No. 12

• The Cardinals saw their magic number to clinch a postseason berth reduced to 10, by virtue of the Nationals' loss to the Mets. The Cards could clinch a playoff spot as early as Sunday, and they would be the first team to do so.

• The Dodgers beat the Angels, 7-5, to push their lead in the NL West to 8 1/2 games over the Giants, who lost to the D-backs, 6-1.

Video: LAD@LAA: Greinke fans five over six nice innings

If the postseason began today ...

AMERICAN LEAGUE
Wild Card: Rangers at Yankees
Division Series: Wild Card at Royals, Astros at Blue Jays

NATIONAL LEAGUE
Wild Card: Cubs at Pirates
Division Series: Wild Card at Cardinals, Mets at Dodgers

2015 POSTSEASON SCHEDULE
AL Wild Card Game: Oct. 6
NL Wild Card Game: Oct. 7
AL Division Series begin: Oct. 8
NL Division Series begin: Oct. 9
NL Championship Series begin: Oct. 16
AL Championship Series begin: Oct. 17
World Series begins: Oct. 27