Phoenix Mercury center Brittney Griner stole the ball from a bad Nneka Ogwumike pass. She then made a two-handed breakaway dunk to get the Merc up 67-42 in the middle of the third quarter. Video is above from the WNBA's YouTube channel. Color analyst Rebecca Lobo was CLEARLY excited at the end of that video clip.
This dunk wasn't about pleasing the crowd, even if the game is a blowout. It is a sign of Griner saying "I MUST BREAK YOU!"
UPDATE: Here are some GIF's where Griner broke the Sparks:
If they weren't broken before that dunk, well, they were after that.