To improve the performance and signal integrity for printed circuit board designs, considering differential pairs in the escape routing is an important issue. Previous works use two-stage approaches, meeting points determining followed by differential pairs connecting, to generate a routing solution. However, existing approaches may produce either non-length-matching solutions or longer length-matching solutions. In this Letter, the authors propose an escape routing model with one-stage optimisation to simultaneously determine median points and route length-matching paths for all differential pairs. Experimental results show that their approach can significantly reduce maximum and average differential-pair skews with 100% length-matching results.