1) Competition 2) Contest 3) Crucial ball game 4) Final Four game 5) Golf terminology 6) Postseason game 7) Prince to stop decider 8) This goes with a tie 9) Tie-breaker 10) Tie-breaking contest 
a series of matches towards the end of the season that determine clubs which are promoted and/or relegated, determine tied league positions or determine qualifiers for continental competitions.[45][183]
[golf] A playoff in the sport of golf is an extra hole, or holes, played when, at the completion of regulation play in a competition or tournament, there is a tie and it is desirable to determine an outright winner. Playoffs are a common occurrence in professional tournaments when the players are readily available to participate at the comp...
a tournament that takes place after a season's schedule has been completed; used to determine a champion.
[Soccer] a tournament that takes place after a season's schedule has been completed; used to determine a champion.
[n] - any final competition to determine a championship
noun any final competition to determine a championship