Here is a few more writings that you might want to read from Blessed Saint Irenaeus,since you want to try and use him to support a reformed point of view.
Chapter XXXVII.Men are possessed of free will, and endowed with the faculty of making a choice. It is not true, therefore, that some are by nature good, and others bad.
http://www.ccel.org/ccel/schaff/anf01.ix.vi.xxxviii.html
How about this from Blessed Saint Irenaeus
“”Chapter IV.The truth is to be found nowhere else but in the Catholic Church, the sole depository of apostolical doctrine. Heresies are of recent formation, and cannot trace their origin up to the apostles.””
http://www.ccel.org/ccel/schaff/anf01.ix.iv.v.html
Shall I go on, Dear Brother?
I'm not trying to use Irenaeus to support the reformed point of view. Anyone reading Irenaeus understands that he had far bigger fish to fry than setting forth a comprehensive systematic theology. This couldn't be done in the Church until Augustine came alone because of all the heresy springing up. (Which is why I normally go back to Augustine.)
I'm simply pointing out there is evidence of the monergistic beliefs of most the early western church fathers. Augustine consolidated their position.
As Augustine's stated; it all goes back to the scriptures, "What do you have that has not been given to you?"