Ghana's Andre Dede Ayew was on target for Olympique Marseille on Sunday night against Saint Etienne.The 23-year-old got the only goal of the match on the stroke of half time through a header.The narrow victory ensured Olympic Marseille continue to mount pressure on PSG and Lyon.All three teams have 38 points after 19 matches but PSG and Lyon are on top of OM as a result of superior goals.Ayew will be absent for Marseille as he takes part in Ghana's campaign at the 2013 Africa Cup of Nations and that will be a big blow for the 1993 Uefa Champions League winners.