Kroy Biermannaced a good parenting test in the midst of his nasty divorce with Kim Zolciak ... and turns out he completed the course before she finished a similar one.
The former NFL star completed a mandatory course in Georgia -- "Parent Education For Separating/Divorcing Families" -- last month and he scored 99% on the quizzes and final exam.
Kroy filed a certificate of completion with the court, obtained by TMZ, and he got his work done before his estranged wife did.
As we reported ... Kim completed a seminar on "Navigating Family Change" on May 25 ... but Kroy's certificate shows he finished his online course May 17, a full week before Kim. BTW ... the course is mandatory for couples with kids seeking a divorce.
Remember, Kroy is asking for sole custody of the estranged couple's four kids ... Kim's asking for primary physical custody, so this is a full-on dogfight.