Antitrust authorities have traditionally used their enforcement powers to support liberalization processes, by prohibiting the exclusionary practices implemented by incumbents to defend themselves from growing competitive pressure arising from market opening. However, in the absence of rigorous and consistent economic analysis and careful assessment of the implications of the regulatory framework, antitrust intervention may distort competitive dynamics in liberalized sectors. The TNT/"Poste Italiane" case is an example of this risk. The Italian antitrust authority contested an overall strategy aimed at preventing the development of competition in some liberalized markets. The administrative courts overturned the conclusions of the Authority, due to several weaknesses in its analysis and lack of evidence of the alleged abuse. The judgment rendered by the State Council will probably represent the leading case on predatory pricing in national antitrust practice in the coming years. The TNT/"Poste Italiane" case also shows the indispensability of a strong and penetrating judicial review to boost the difficult transition to an economic approach in the enforcement of Article 102 Tfeu.