Nowadays aesthetics, comfort and functionality are the most important characteristics of sports garments. To achieve comfort, sports garments are manufactured as combined fractions made of different fabrics providing different characteristics and designs. Preparing patterns which provide the best fit for the tightfit garments is much harder than the loose fit ones. To find the best fit, many prototypes have to be made, but the manufacturers do not have the necessary time. Thus, 3D Flattening systems provide a way out for the industry, but especially for the sportswear manufacturers.In this study, firstly, a virtual male model was formed. Afterwards, a fractioned tight-fit male sweatshirt model was designed on this virtual model via Opititex 3D Flattener. As the model was created, the pattern was obtained simultaneously. When the design was completed, 2D patterns were obtained automatically. After virtual stitches and other details were applied, the sweatshirt was dressed on the created male model in order to determine the fit. Eventually, fit of the created design was evaluated.