This study investigated the effects of a one-to-one intervention designed to increase social support and improve performance using a single-subject multiple baseline design. Participants were 3 high-level male golfers, mean age 25.0 years (SD = 2.6). All participants reported significantly higher levels of emotional, esteem, informational, and tangible support in the intervention phase compared to the baseline phase (ts = -2.35 to -21.80, ps < .01). The performance of all participants improved during the intervention phase compared to the baseline phase. Participant A improved by an average of .90 shots per round, Participant B by 1.33 shots per round, and Participant C by 3.10 shots per round. The effectiveness of the intervention upon performance outcome was supported by a χ² analysis (χ² (1) = 4.80, p < .05). The results indicate that a one-to-one intervention may be a useful strategy to increase social support and improve performance.