Chris Brown's word is his bond -- weeks after the singer promised to reward the fan who returned his $22 thousand watch at the VMAs ... he came through.

Breezy rolled through the fan's hometown of Cincinnati last night ... and he hooked the girl, Alisha,  up with 2 great seats to his concert at the Riverbend Music Center.

Chris also met with Alisha to thank her face-to-face ... then invited her to hang with him and his entourage before the show to eat some cake.  And Chris threw in a signed picture for good measure.

As we previously reported, CB accidentally tossed the diamond-encrusted Rolex into the crowd at the MTV awards last month ... Alisha caught it and gave it to Chris' bouncer.