We perform direct diagrammatic calculations of the anomalous dimensions of twist-two operators in extended $N=2$ and $N=4$ super Yang-Mills theories (SYM). In the case of $N=4$ SYM, we compute the four-loop anomalous dimension of the twist-two operator for several fixed values of Lorentz spin. This is the first direct diagrammatic calculation of this kind, and we confirm results previously obtained by means of integrability. For $N=2$ SYM, we obtain the general result for the anomalous dimension at third order of perturbation theory and find the three-loop Cusp anomalous dimension.