Aim: The aim of this randomized clinical trial was to assess the performance of a self-adhesive, bulk-fill hybrid (Surefil OneTM, Dentsply Sirona, Konstanz, Germany) versus incremental, nanohybrid resin composite (Ceram.x® SphereTEC™ one Universal Nano-Ceramic Restorative, Dentsply Sirona, Konstanz, Germany) in restoring compound class II lesions over one-year follow up period. Materials and Methods: Sixty-two participants were randomly assigned to each group. All materials were placed upon manufacturer's instructions. Restorations were assessed after 6- and 12-months intervals using the modified USPHS clinical criteria. Categorical data were analyzed using Fisher's exact and McNemar's tests for inter and intragroup comparisons respectively. Ordinal data were analyzed using Mann-Whitney U and Friedman's test followed by Nemenyi post hoc test for inter and intragroup comparisons respectively. Survival analysis was done using Kaplan-Meier estimate and log-rank test. Results: Except for retention at 6 months, for all parameters and at both time intervals, there was a significant difference between the two groups with the control group having significantly higher percentage of cases with alpha score (p<0.05). For retention, surface roughness, recurrent caries, color match, anatomic form and proximal contact, there was a significant reduction in the percentage of cases with alpha score for the intervention group only after 12 months (p<0.05). Conclusion: Incremental, nanohybrid resin composite showed superior clinical performance than the self-adhesive, bulk-fill resin hybrid over one-year follow up.