With two wins and a draw from their first three games, the visitors travelled to Etienne hoping to maintain their unbeaten start before the two-week international break.
However, their afternoon got off to a rotten start when defender Alexander Djiku was given a straight red card after just four minutes.
It seemed only a matter of time before Etienne broke the deadlock, and it came on 20 minutes when defenfer Loic Perrin headed home a corner.
However, the visitors came back strong and secured parity at the break when Gael Danic somehow found the net from the tightest of angles four minutes before the interval.
Christophe Galtier's side toiled for much of the second period in their attempts to wrestle the game back from Bastia, but it proved worth the wait.
On 62 minutes, Eysseric established the hosts' lead by sending a fierce effort beyond the reach Jesper Hansen from all of 30 yards.
It went from bad to worse for Bastia in the final quarter when Francois Kamano was dismissed for an ugly collision with Stephane Ruffier and Perrin to leave the visitors with nine men and 17 minutes to find an equaliser.
From there, Etienne closed the game out with ease to record back-to-back wins, having beaten Lorient 1-0 away last weekend.