Justin Timberlake's always looking out for his fans ... slamming the brakes on his show in Texas to point out one who seemingly needed medical assistance.
The singer-songwriter hit the stage at the Moody Center -- an arena at the University of Texas at Austin -- Saturday night ... and, during his show, he stopped and shouted for the house lights to come up.
Check out the video of the incident ... Justin apologizes to the crowd for pausing the show before pointing at a fan he says is about five rows from the stage who desperately needs assistance.
Event staff seems to rush in pretty quick, and from the way JT's reacting, it looks like it wasn't too serious an incident ... still, scary situation for both the pop star and the audience, ya gotta think.
An eyewitness tells us the staff members checked out the fan, and the fan later returned to their seat. Paramedics weren't called to the scene.
JT's just one of many stars who's had to stop their show to help in serious medical situations. Adam Sandler, Louis Tomlinson, John Mayer and Taylor Swift have all had to pause shows to help fans out.
Justin's got a couple days off ... performing next on Tuesday in Fort Worth, Texas. He's on his "Forget Tomorrow World Tour" -- a totally solo tour, though there are serious rumblings about an *NSYNC reunion.
But, for now, Justin's got the stage all to himself ... and, he's keeping a sharp eye on his loyal supporters from it.