A novel systematic/integrated mechanism reduction strategy for skeletal level reduction of a large-scale detailed chemical mechanism is developed and presented with an example of n-decane oxidization under engine-relevant conditions. The main purpose of the proposed reduction methodology is to utilize the advantages of various reduction approaches in order to minimize the size of a skeletal mechanism while keeping the prediction accuracy and computational cost within a satisfactory trade-off. A new skeletal mechanism of n-decane is developed consisting of 96- species and 256 reactions, which achieves 95% reduction of species size compared to that of a detailed mechanism (2111 species, 8157 reactions). Comprehensive kinetic validations of the 96species mechanism are carried out using available experimental data in the literature including shock tube, jet-stirred reactor, laminar flame, and oppose flow diffusion flame covering a wide range of temperatures (600-1650 K), pressures (1-80 atm), and equivalence ratios (0.2-2.0). Moreover, the 96-species mechanism is applied to modeling ignition delay in an ignition quality tester for spray combustion by using multidimensional simulations to assess its predictive capability. The overall performances of the 96species mechanism are found to accurately predict the fundamental combustion phenomena and spray-induced autoignition processes, suggesting the potential use of integrated/systematic reduction strategy for constructing skeletal mechanisms for large-scale surrogate fuels.