BaBar's observation of significant deviations of the pion transition form factor (TFF) from the asymptotic expectation with Q(2) > 9 GeV2 has brought about a serious crisis to the fundamental picture established for such a simple q (q) over bar system by perturbative QCD, i.e. the dominance of collinear factorization at high momentum transfers for the pion TFF. We show that non-factorizable contributions due to open flavors in gamma gamma* -> pi(0) could be an important source that contaminates the pQCD asymptotic limit and causes such deviations with Q2 > 9 GeV2. Within an effective Lagrangian approach, the non-factorizable amplitudes can be related to intermediate hadron loops, i.e. K-(*()) and D-(*()) etc., and their corrections to the pi(0) and eta TFFs can be estimated.