Liverpool began the game enjoying plenty of possession but failing with final ball against a Marseille side short on confident on their travels having lost six of their last seven away European outings.
A scrappy opening period finally saw Marseille break quickly and Ben Arfa beat three men but the move fizzled out with Bakari Kone appealing in vain for a penalty.
Liverpool's measured build-up finally saw an end product on 21 minutes
as Torres crossed and Kuyt's diving header was scrambled for a corner.
Within a minute though the Reds took the lead as a deep cross from the right was headed firmly home by the unmarked Steven Gerrard.
For a few moments the visitor's looked a dispirited bunch but then began to use the pace and trickery of their wide men and suddenly Liverpool where under pressure.
Taye Taiwo hit a 30 yard drive which saw Pepe Reina at full stretch palm behind. From the resulting corner Reina failed to collect and Ronald Zubar headed wide,
Marseille continued to push forward knowing nothing less than a win would continue their interest in the Champions League.
The crowd began to get restless as Liverpool became careless in possession and were only placated on the stroke of half time as Fabio Aurelio's drive brought a scrambled save from Steve Mandanda.
The second half began in similar fashion and Torres just failed to get on the end of a loose ball in the six yard box.
Liverpool then looked vulnerable as twice in quick succession Mamadou Niang got behind the Reds defence but fails to make it count.
Marseille began playing with more conviction knowing their hosts had not kept a clean sheet in Group D.
Arfa wriggles to the by-line but his pass across the six yard box fails to find a team-mate.
The pressure on the home side is only relieved when an Albert Riera shot is beaten away by Mandanda.
Reina keeps Liverpool in front with a marvellous save from an Arfa free kick then a desperate block from substitute Andrea Dossena prevents an equaliser by Niang.
The Reds struggled to keep possession and Marseille took full advantage only lacking the final ball to make Liverpool pay for a below par second half display.
With time ticking down a minor scuffle broke out as Javier Mascherano brings down substitute Mathieu Valbuena and is booked.
Three minutes of added time and Liverpool hang on for a less than deserved win.
Benitez accepted his side struggled on the night.
"It was a strange game. We scored a goal then they attacked and we counter attacked.
"We looked in control but our final ball was never good enough and they had the same problem.
"The game was too open and against a team with pace and ability it is always going to be a problem.
"They played with three strikers and two support players and if they have pace and ability it is never easy. We tried to find Torres whenever possible but were too quick.
"The main thing today was to win and progress and that is what we did but we analyse what went wrong later."