On the first day of what was only his third premier class test, the 2012 Moto2 champion lapped within five hundredths of a second of last year's championship protagonists Jorge Lorenzo and Dani Pedrosa.
While Marquez played down the importance of such times, he admitted he had not expected to be so quick so soon.
"I did not expect to be at the level of Dani, Valentino and Lorenzo," Marquez admitted.
"The times are not important now, because they are trying lots of things out, but yes, it is better to be up there than suffering a little further back."
Marquez said he was yet to find the limit of Honda's RC213V, particularly because he is yet to adapt the bike to his own style.
"At the moment, [the bike] is still in charge in some aspects," he explained.
"I felt very good, better than I expected with the bike, but I have not found the limit right now.
"I'm seeing that on some corners I can play around with my body position, but I still need to adapt to the bike.
"[The first Sepang test] we had it so that it was me who adapted to the bike.
"For the next test we will go with the idea of trying to suit the bike to my riding style."