in the Tennis.ini (or the .ini of your current Profile), change this line, under [3dEngine], from :
DevMode = 0
DevMode = 1
It'll add a button on the match screen which allows you to chose to win, lose, or accept the result.
In DevMode, the game isn't saved when you exit by clicking on the little cross on top right of the window.
== Mana Games ==
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