Red wings
celtics
the world cup (soccer)
Football Playoff Game- Cardinals and ?
In what sport? Many sports have playoff and championship series.
As of September 2013 - CBA of Lincroft, NJ - Boys HS Cross Country - 323 straight Dual Meet wins dating back to 1973.
baseball
Pole Vault
Ski Jumping
Sacramento
mount cordial soccer team
speed skating
Baseball can go as long as needed until a winner is crowned