Paulina Gretzky -- Perfecting Stroke Technique

Paulina Gretzky's pro-golfer fiance is really rubbing off on her ... 'cause the model's swing is looking as tight as her ass in those yoga pants.

The Great One's biggest accomplishment posted the video to Instagram today ... and credits Dustin Johnson (her golfer husband-to-be) for improving her stroke.

"Getting a little better thanks to my coach @djohnsonpga."

Of course, Paulina probably inherited some of her dad's hand-eye coordination ... and luckily, all of her mother's good looks.