The St Louis Cardinals moved a step closer to clinching the National League Central division with a hard-fought 3-0 win over the Pittsburgh Pirates.
Mark Reynolds hit a two-run home run and Jon Jay hit a single in the ninth at PNC Park as the Cards registered their 99th win of the season and move to within one game of claiming the division title.
At AT&T Park, the San Francisco Giants stayed alive in their quest to secure a play-off berth as they delayed the Dodgers clinching of the National League West with a 3-2 walk-off win.
Alejandro De Aza's sacrifice fly in the 12 innings saw the Giants hand their California rivals a fourth defeat in a row following solid outings by pitchers Zach Grienke and Jake Peavy.
The Toronto Blue Jays moved to within two wins of clinching the American League East division with a come-from-behind 4-3 win over the Baltimore Orioles at Camden Yards.
Dioner Navarro, Kevin Pillar and Justin Smoak all had RBI's as the Canadians turned around a 3-1 deficit to win their 91st game of the season.
Chris Denorfia's walk-off home run saw the Chicago Cubs claim a tight 1-0 win over the Kansas City Royals at Wrigley Field in a match both sides used to rest some key players, having both already clinched play-off berths.
The Houston Astros, meanwhile, took another step to claiming the final play-off spot still up for grabs in the National League as Chris Carter smashed a solo home run in the seventh as thy beat the Seattle Mariners 3-2.
The Los Angeles Angels also stayed in the hunt for the final Wild Card berth as they walked-off the Oakland Athletics in dramatic fashion in Anaheim, David Murphy taking advantage of Edward Mujica's ninth-inning error in a 5-4 win to keep them a half a game back of the Astros.
Monday's Major League Baseball results:
Reds 1, Nationals 5
Red Sox 5, Yankees 1
Blue Jays 4, Orioles 3
Cardinals 3, Pirates 0
Twins 4, Indians 2
Royals 0, Cubs 1
Tigers 7, Rangers 4
Athletics 4, Angels 5
Astros 3, Mariners 2
Dodgers 2, Giants 3