Shania Twain Falls Onstage During Performance in Chicago

Shania Twain had a moment during her concert in Chicago Saturday night …she tripped and fell on her butt, but made a quick recovery and finished strong.

The country music legend was belting out her tune, "Don’t Be Stupid,” at Credit Union 1 Amphitheater in Tinley Park when she wiped out while walking across the stage.

The video, obtained by TMZ, captured the moment Shania tumbled to the floor, but she kept singing, jumped back up to her feet and polished off the song.

We're told Shania did not look injured at all ... and she continued performing without taking a break.

Eyewitnesses also tell us the packed crowd did not react when Shania took her spill ... apparently because she seemed totally fine.