Only yesterday Wenger claimed Marseille, Rafael Benitez’s Napoli and last year’s runners-up Borussia Dortmund made Group F the hardest of this year’s competition.
The Frenchman also conceded that unless their injury situation improved — currently eight first-team squad members are out — then they would struggle to make it out of the group for the first time since the 1999/2000 season.
Wenger will therefore have been all the more relieved to see his side pick up yet another win on the road last night on the French south coast.
Theo Walcott and Aaron Ramsey’s second-half strikes proved the difference at the half-finished Stade Velodrome, where the hosts dominated for large periods of the match.
Marseille, back in the competition after a year’s absence, edged the first half, with Andre Ayew and Andre-Pierre Gignac coming closest.
A Mesut Ozil cross was nodded goalwards by Walcott, only for Nicolas N’Koulou to clear from danger in what was Arsenal’s best moment early on.
Walcott was proving a pest in the early stages, forcing Steve Mandanda into action before landing a chip on the roof of the net, albeit from an offside position.
The tempo soon calmed, though, with both sides content to keep possession as they searched for an opener.
Rod Fanni was inches away from grabbing the opener moments into the second half, before Kieran Gibbs saved Per Mertesacker’s blushes by clearing his miskick off the line as Gignac waited to nod into an empty net.
It was a moment that proved decisive as another defensive mistake at the other end put Arsenal in control.
Jeremy Morel misread a Gibbs cross, allowing Walcott time to rifle into the roof of the net and quieten those who had criticised his finishing in Saturday’s 3-1 win at Sunderland.
Ozil also came close in the closing stages, before Ramsey put the match out of sight by shrugging off Marseille defenders to fire home.
Jordan Ayew struck home a stoppage time penalty after Ramsey was adjudged to have tripped Ayew, but it was a mere consolation.
Wenger praised his players for producing a performance of “patience and experience”.
“It was important for us not to give the first goal away. “We were a bit timid overall and in the second half they dropped and we took advantage of our good moments in the game.
“It was a victory linked with patience and experience, even if we were not flamboyant tonight. But we start with three points and that is good.
MARSEILLE: Mandanda, Fanni, N’Koulou, Lucas Mendes, Morel, Romao, Imbula (Thauvin 79), Payet (Jordan Ayew 73), Valbuena (Khelifa 90), Andre Ayew, Gignac.
ARSENAL: Szczesny, Sagna, Mertesacker, Koscielny, Gibbs, Flamini (Miyaichi 90), Ramsey, Walcott (Monreal 78), Wilshere, Ozil, Giroud.
Referee: Olegario Benquerenca (Portugal).