Marseille warmed up for their Champions League trip to Borussia Dortmund by winning 2-0 at Lorient in Ligue 1 on Saturday.
After a first half of few chances in Brittany, OM got the breakthrough just before the hour mark when the excellent Mathieu Valbuena netted from a free-kick just over 20 yards out.
The little French international had scored the only goal when OM won at the Stade du Moustoir last season and it looked as if his latest strike would secure an identical result this time.
However, as Lorient pressed forward in search of an equaliser, Marseille made certain of the points in stoppage time, Andre Ayew firing low past goalkeeper Fabien Audard at his near post for his first goal of the campaign.
The win was Marseille's second in five days following their 2-1 victory at home against Saint-Etienne in midweek and allowed them to climb provisionally into second place in the Ligue 1 table, behind leaders Monaco on goal difference and two points ahead of Paris Saint-Germain.
Marseille travel to Dortmund on Tuesday looking for their first points in Champions League Group F after losing 2-1 at home to Arsenal in their opening game.
Unbeaten PSG are in action later on Saturday, at home to Toulouse, while Monaco, who are also still to lose, travel to Reims on Sunday evening.
Saturday's fixture card also sees Lyon entertain 2011 double-winners Lille at the Stade de Gerland, while Sunday's highlight is the Breton derby between Rennes and Nantes.