Soliciting after-the-fact advice on how I should have handled a social dilemma.

Recently went to a reserved-seating event and ended up without a companion at the last minute, so I had an empty seat (which I had paid for) between me and the lady at the end of the row. After the show was underway, a woman -- apparently a friend to the lady on the end -- plopped down in the empty seat.

That didn't really bother me, since I didn't need an empty seat. However, the woman's perfume was so overpowering that I felt less than comfortable for the rest of the evening. I didn't want to be rude and tell her to move, but I also didn't want to inhale her artificial scent for the next 90 minutes. What to do?
I just suffered in silence. The show was enjoyable, but I would have been a lot more comfortable with an empty seat. Anybody got advice on how to gracefully handle the situation without coming across as a selfish cranky old man?