Hi everybody! The best way to gain this trophy is to go into quick play and play on any 18 hole course (i found East Lake Golf Course easiest) NOW here is the good bit so be careful.
YOU HAVE TO PUT THE ROUND OF GOLF ON TOURNAMENT DIFFICULTY, now do the 1st hole on that setting, then when you get to hole 2 and put it back on your preferred setting. Play your round until hole 18 and before you tee off put it back on tournament difficulty again and finish it. after that is done you finish up and then trophy pops.
It really is that simple. hope this helps