Lorenzo led the last round in Spain at first, but was overhauled by Honda's Dani Pedrosa and then denied second when Marquez barged past at the final corner.
The Yamaha rider had been concerned about long-run pace following that disappointment and remained unsure about his bike's speed in Friday practice at Le Mans.
But by qualifying he felt the problem was sorted, leaving him confident he can fight for victory despite Marquez beating him to pole by 0.030 seconds.
"All weekend we've been working pretty much to improve the feeling on the front tyre, where we had some difficulties at Jerez, and trying to improve the bike to keep a more consistent pace," Lorenzo said.
"I think we've got it.
"I also concentrated on doing a very fast lap but unfortunately I couldn't beat Marc today because he was really fast.
"But our main target was to improve the bike for the race and I think we've done that. We'll see tomorrow."
Lorenzo has had to settle for third behind the Hondas in the last two grands prix after winning the Qatar season-opener.
He is third in the championship, four points behind Marquez and one behind Pedrosa.