Removing rows from the dataframe 1 where equivalent row in dataframe2 has null values

I have two data frames and I am using the last columns from both the data frames to calculate classification metrics.

I want to make sure the values are correct, one of my data-frames is being loaded from database and there are chances that I might get NaN values in that data frame.

I want to delete the row which consist of NaN values from both the data frames, my other dataframe won't have any NaN but I want to check NaN values in first data frame and delete the equivalent row from first and second data frame so that my classification happens only on real values.

I am not sure how to achieve this