The solution is:
d3-e3! (only one disc) with the threat of
e5:3-e3 (scoring the last point for a win). White can only respond with
c5:3-e3 (scoring the 4th point), which however opens the path for
e5:2-a5.
Note that if White chooses
c5-e3, Blue moves
e5:3-c5 and after White
c5:2-e3 the winning move for Blue is
c4:4-c5.