Bielsa laments missed chances in Lorient draw
Dimitri Payet had put the Ligue 1 leaders ahead just after the half-hour mark, but Jordan Ayew levelled from the penalty spot in the first half.
And Bielsa's men were unable to find a winner against the 14th-placed side, giving Paris Saint-Germain the chance to go above them on Wednesday.
Bielsa said there was a gulf in quality between the two teams, but Marseille simply failed to take advantage on the scoreboard.
"The final score doesn't reflect the difference between both sides. So there's a feeling of dissatisfaction that remains," he told a news conference.
"We had more than enough chances in order to make the difference. We weren't able to create chances for ourselves, but we didn't allow them to create many either.
"When you can't convert the chances you get, you remain unsatisfied. When you see the result, you realise that we couldn't show the difference between the two teams on the pitch."