Last year in Auckland a rugby league team in the premier club competition (Pt Chevalier Pirates) fielded a 'c' team (it was their senior b team which is their third team below their reserves) in their last game of the regular season.
They were guaranteed first spot, and the reason they did this was so that their opponents could hammer them and move into 4th spot on points differential.
The semi final format was 1 v 4, 2 v 3.
Pt Chev didn't want to play the team that was basically a lock for 4th spot as they had lost to them twice during the season.
They had to lose by about 50 pts and ended up losing something like 100-0.
The result was Auckland Rugby League had an inquiry, and threw them out of the competition for bringing the game into disrepute.
The correct decision.