Oxidative stress is a critical driver of lung cancer progression, causing DNA and protein instability and supporting oncogenic transformation. At the metabolic level, reactive oxygen species (ROS) can oxidatively modify metabolic enzymes and reroute metabolic pathways according to tumor needs. Here, particularly important are thiol groups which act as main carriers of redox signaling, but due to their highly reactive nature are rarely analyzed in the clinical setting. To accurately address the cross talk between redox signaling and metabolism in lung cancer, we collected tumor as well as neighboring (not directly tumor-adjacent) healthy tissue from 70 individuals with non-small cell lung cancer. We took special precautions: samples were collected at the point of surgical tumor removal and preserved immediately in a thiol-quenching solution, before being subjected to multi-omics analysis. As a result of such unbiased redox approach we report evidence for the first time of higher oxidation of a number of key metabolic enzymes in tumor tissue, especially those involved in glucose metabolism, including phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK) and pyruvate kinase M (PKM). We furthermore demonstrate indications of active efforts by the tumor to maintain oxidative metabolism amid the prominent rise of intracellular oxidative stress. Lastly, we report both redox and protein level deactivation of glyoxalase system. This might result in higher excretion of toxic methylglyoxal, potentially supporting cancer progression.