Diana Taurasi's wallet is now $2,500 lighter -- the Phoenix Mercury star was just fined for shoving a referee during Game 2 of the WNBA Finals on Wednesday.
The incident happened in the 2nd quarter ... when Taurasi's teammate, Sophie Cunningham, missed a layup and went for the loose ball.
Cunningham ended up on the ground trying to corral the basketball ... and that's when Chicago Sky's Kahleah Copper went to tie her up, piling on top of her on the floor.
The two got a little heated -- so referee Tiara Cruse ran in to hold Copper back.