Although their first major confrontation occurred when the Mets swept the Braves in the 1969 NLCS, en route to their first World Series championship, the first playoff series won by an expansion team (also the first playoff appearance by an expansion team), the rivalry did not become especially heated until the 1994 season when division realignment put both the Mets and the Braves in the NL East division. During this time the Braves became one of the most dominant teams in professional baseball, earning 14 straight division titles through 2005, including five world series berths, and one world series championship during the 1995 season. The rivalry remained heated through the early 2000s.