Find the brilliant move by white.

DLB777
Optimissed wrote:

Sorry.

Qxa4 ....c2-c1 queens pawn

Now white's queen is cut off from the play and black's queen on c1 commands the area near white's king.

However, if white plays a7-a8 instead, queening the pawn, white is a queen up and has a won game. Black cannot get near white's king.

Oh. Ok!  Thank you for taking the time to explain that! I see what you mean now. Much appreciated. 😉