The results are very similar, so I think it's pretty safe to say that for the moment, Lee Fisher leads Rob Portman, though by a hair.
Quinnipiac has Fisher up 42-40 (MoE 3), despite the poll having Ohio oppose the "federal health care overhaul" 55-36. PPP's results are only slightly different, showing Fisher up 40-38 (MoE 4.5) and "President Obama's health care plan" opposed 53-38.
These are large margins of opposition to the PPACA. Is Portman hurting himself by not coming out more strongly against it, contrary to the conventional wisdom that a moderate approach is safest in a swingy state like Ohio, and too much opposition to the President's most important accomplishment to date is a bad idea in a state he carried? I think it could be the case.
Repeal, then replace! Nobody likes Obamacare so let's get loud against it!