Abstract: Objective: Functional near-infrared spectroscopy (fNIRS) hyperscanning was employed to investigate the inter-brain synchronization (IBS) mechanism underlying cooperation in table tennis doubles. Methods: Two experiments were conducted in this study. The first experiment was conducted in a laboratory, the frontal and temporal lobe activity from 41 pairs of table tennis athletes during a cooperative anticipation task were recorded, and IBS was analyzed in relation to cooperative performance scores. An amateur group and a non-table-tennis cooperation task served as controls. The second experiment was conducted in a real-world field, the frontal lobe activity of 30 pairs of athletes during doubles matches was collected to evaluate the cross-situational stability of key neural markers. Results: 1) In the laboratory cooperative anticipation task, the IBS was increased significantly in multiple channels covering the dorsolateral prefrontal cortex (dLPFC). In addition, the IBS in the left dLPFC was positively correlated with cooperative performance scores. 2) These IBS enhancement patterns were not observed in both the amateur group and the non-table-tennis cooperation task. 3) In the real-world field setting, the enhanced IBS in the left dLPFC was stable, and it increased IBS in the frontopolar cortex and Broca's area (pars triangularis), but this pattern was not evident in the amateur group. 4) Pairing duration did not affect IBS during cooperative anticipation in the laboratory. However, in the field experiment, longer pairing duration was associated with significantly enhanced IBS in the frontopolar region. Conclusions: 1) In right-handed table tennis doubles athletes, enhanced IBS in the left dLPFC represents a potential neural substrate driving cooperative performance and appears insensitive to pairing duration. 2) Real-world doubles are highly complex, involving dynamic adjustment and non-verbal communication, thereby providing conditions that reveal the neural advantages of accumulated pairing experience. 3) The observed IBS enhancement during table tennis doubles cooperation is likely jointly determined by sport-specific characteristics and long-term specialized training.