Bielsa insisted the "the result [was] misleading" due to the number of goalscoring opportunities created by both teams, although he was impressed by Marseille's finishing.
Toulouse had 16 shots at their Stadium Municipal with just two on target, while Marseille shot 11 times, hitting the target with eight.
"The result is misleading because Toulouse had as many opportunities as us but the difference was in terms of efficiency," Bielsa said.
"No doubt that victory is deserved, Marseille made a great effort to win but the difference on the scoreboard could have been smaller."
For the second straight league game, Bielsa selected Michy Batshuayi at the point of attack instead of Andre-Pierre Gignac.
Batshuayi struck twice in the first half for Marseille, including the opening goal in just the second minute, while Gignac replaced the Belgian with 29 minutes remaining before eventually scoring the visitors' sixth.
Gignac started the Ligue 1 campaign with 10 goals in as many matches and remains second in the goalscoring standings with 16 behind Lyon's Alexandre Lacazette (21), while Batshuayi has six goals, including four in the past three games.
But Bielsa denied he has any problem with Gignac and was unmoved by claims the 29-year-old striker's form has dropped.
"It may be that one or the other has more playing time by the end of the season but I do not think Gignac has lost anything from earlier this season," the Argentine coach said.
"Currently, [what is most] important for Gignac is that the last two times he came into the game, he scored."
The win took Marseille into second in Ligue 1's table with 53 points, ahead of Paris Saint-Germain on goal difference, while Lyon (54) remain on top.
Both Lyon and PSG have yet to play this weekend.
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