All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Praying in a place which is specified for women's prayer is permissible for men as long as there are other men praying, and provided that one was not alone in the row. Basically, men's rows should be next to the Imam, then children's rows and then women's ones behind the children. In a sound Hadeeth, Anas ibn Maalik said: “An orphan and I prayed behind the Messenger of Allah two Rak’ahs and my mother (or grandmother) prayed behind us.” [Al-Bukhari and Muslim]
Praying alone in a row is incorrect if there is a place with other rows. Prophet Muhammad said: “The prayer of a person standing alone behind the rows is not valid.” [Ahmad]
However, it is disliked to pray in that place (women’s section) if the women are found there at the time of prayer. Prophet said: “The best rows for men are the first rows, and the worst ones are the last ones, and the best rows for women are the last ones, and the worst rows for them are the first ones.”
Allah knows best.