Beyonce Knowles is officially a big sister again -- a DNA test has confirmed that Mathew Knowles is the father of Alexsandra Wright's brand new baby boy ... sources tell TMZ.
With the DNA test a match, we're told lawyers for Knowles and Wright are in the final stages of negotiating a settlement for baby Nixon's child support.
Wright filed a paternity suit last October against Knowles -- who was temporarily ordered to pay $8,200 in monthly child support.
Wright claims she had an 18 month affair with Knowles.
As far as we know, nothing's tricky about Nixon .... so far