Walcott's goal came late in the game after Arsenal had soaked up everything L'OM had to offer. Kieran Gibbs, who was superb all night at left-back, crossed for the England flyer to smash the ball home after Jeremy Morel's attempted clearance.
The second goal came from the boot of Ramsey, who added his seventh goal of the season. The Welshman has been brilliant this term and is the real inspiration behind Arsenal's early good form.
He took his lucky No. 7 with devastating ease. Having controlled the ball, he evaded two tackles before firing in from the edge of the box. It was a great goal despite the slight deflection.
In truth, the game was best described as a tactical affair. Marseille created the better opportunities in a tight game. Mathieu Valbuena impressed from center midfield for the French team, but they lacked a cutting edge up front, where Arsenal dealt with them easily.
Marseille did manage to score a late consolation goal after Ramsey took Andre Ayew down after his own poor control in the penalty area. Ayew then dusted himself off and stepped up to score, but it was a case of too little, too late.
It was almost, in many ways, the perfect away performance by Arsene Wenger and his team.
Here, Bleacher Report offers five things we learned from Marseille vs. Arsenal...