The New York Mets and Toronto Blue Jays are the latest two teams to secure their places in baseball's post-season.
The Mets beat Cincinnati 12-2 to clinch the National League East crown while the Blue Jays are guaranteed at least an American League wildcard place after beating the Tampa Bay Rays 10-8.
They were boosted by two home runs from Jose Bautista, although it turned out they had actually sealed their play-off berth on Friday, without actually realising until Saturday morning.
But the Blue Jays avoided any kind of pre-game celebration and went on to claim another vital victory in their bid to win the East crown, maintaining their four-game lead over the New York Yankees heading into the final week.
Toronto have not been to the post-season since 1993 when they won their second successive World Series.
"We had a little talk before the game that we weren't going to do this, do a big celebration," Bautista said,
"Even though getting into the play-offs means a whole lot, especially for our fan base, which has been waiting for so long, we want to win the division and that's still the goal. But we just got in here and ... the emotion, the excitement, everything took over, and we just started celebrating."
The Mets' wait to get to the play-offs stretched back to 2006 and they ended that in style, with Lucas Duda hitting a first-innings grand slam to send them on their way to victory.
They struggled for a long spell in the height of summer but have scored 300 runs since August 1 - the most in the majors - to win 35 of their last 52 games and secure the division crown.
"We've waited a long time for this," manager Terry Collins said. "This is tremendous."
Elsewhere, the Los Angeles Dodgers remain favourites to land the National League West despite an 8-6 defeat in Colorado.
Their 'magic number' remains at two after the San Francisco Giants beat the Oakland Athletics 14-10, Jarrett Parker becoming the first Giants rookie to hit three home runs and seven RBI in a game since the legendary Willie Mays achieved the feat 54 years ago.
The Dodgers need a combination of two wins or two Giants defeats to secure their play-off place.
Texas saw their AL West lead cut to three-and-a-half games by the Houston Astros, who hit six home runs in a 9-7 win over the Rangers. Texas' magic number is five, and they face the Astros again on Sunday.
The remaining race comes for the American League wildcards, with the Yankees in prime position to take one of them if they fail to catch the Blue Jays for the divisional title.
The Astros, the Los Angeles Angels and Minnesota Twins are covered by only a game-and-a-half, with Cleveland three games back and Baltimore clinging on to slim hopes.
