Robbie Keane -- I Hooked Up My Gas Samaritan ... FREE GALAXY TIX!! (VIDEO)

ATTENTION SOUTHERN CALIFORNIA ... if you see LA Galaxy star Robbie Keane out of gas on the side of road ... help him out ... 'cause it just might net you some free Galaxy tickets.

We got Robbie out in L.A. and talked to him about the little mishap he had recently ... where he freakin' ran out of gas on the streets, and had to be rescued by a good-hearted Angelino.

Robbie big upped Warren Williams -- the dude who helped him out -- on social media, but what our guy (and quite frankly the rest of the world) wanted to know was ... what ELSE does the hero get?

Check out the clip -- Robbie says he and his hero exchanged numbers at the scene of the great emptying ... and he's gonna treat him to a night out to watch the Galaxy play in Carson.

Good job all around ... but Robbie, pay attention to your damn gauge, bro.