Here is a game from the 2008 German "Schachbundesliga", FM Richter - IM Meins with full annotations and commentary:
In this game we saw the Queens exchanged very early in the game. Then the game was simplified into a Rook and Knight endgame where both sides fought hard to keep the game in balance. The final stage took place with a pure Knight endgame. Towards the end it may have seemed simple with so few pieces remaining but even endgames such as this are very dangerous and one wrong step can cost the game. Even master level players such as in the game above can misplay endgames as white did here.
So the next time you enter an endgame which appears to be simple and safe remember this example and take extreme caution when choosing your moves towards the end of the game.