Hi, i'm learning prokofiev's piano sonata no. 3 op. 28 and everything was going fine until I reached measure 27, supposedly it is a triplet so the rhythm should be...

LA la la LA la la


But when I play it, the rhythm becomes...

la LA la la LA la


I suspect the problem is because the left hand starts playing on the 2nd beat and not on the 1st beat. So how should it be played, should the first beat be emphasized or does the composer intend for the emphasis to be on the weaker second beat? This is driving me nuts! lol... I have listened to recordings by Emil Gilels and other younger musicians like Daniil Trifonov and Aimi Kobayashi on youtube and their performances seem to give the feeling of an emphasized second beat. However, my teacher insists that the first beat should be emphasized.

I'm in a quandary here, hopefully someone could help me? Please?