Al Ain secured a 2-0 away win over Ittihad Kalba in the first leg of the ADIB Cup's semi-final.
Rahimi's clinical finish from a close range put Al Ain ahead in the stoppage time of the first half.
Laba Kodjo should have doubled the lead when his effort from the oustide of the box went above the post.
Mehdi Ghayedi was so close to hit the equalizer as his powerful shot smashed the crossbar one minute after the hour-mark.
Mohamed Abbas made it 2-0 at the death when lashed the ball into the back of the net from a close range.