Tiesto -- one of the most popular DJ's on the planet -- was rushed to a hospital Friday night in San Jose ... after he hit his head on the giant TV screen above his turntables.

Tiesto was supposed to play a show last night in San Jose ... but whacked his head on the LED as he made his way to the stage -- and went down HARD!

According to reports, the DJ tried to play his set anyway -- but management said no.

Tiesto updated his fans a few hours later saying he got a a couple stitches and doctors said he suffered a concussion.

For now, he's gotta stay off his feet for a few days ... meaning his set at a concert in L.A. tonight is cancelled.

Sorry EDM kids.