The Atlanta Braves, Oakland Athletics and St. Louis Cardinals can start planning for the playoffs.
All three teams clinched postseason spots Sunday. They joined Boston and the Los Angeles Dodgers with guaranteed dates to keep playing in October.
The Braves won their first National League East crown since 2005 and the Athletics took their second straight American League West title.
The Cardinals are still trying to win the N.L. Central, but are assured of at least a wild-card berth.
With a week left in the regular season, the race for the two A.L. wild-card spots is still tangled. Tampa Bay is a half-game ahead of Cleveland, with Texas 11/2 games behind the Indians. Kansas City, the New York and Baltimore are lagging further behind.
In the N.L., Cincinnati and Pittsburgh are tied for the wild-card slots.