Stucken in mission, please help me !

[Chicken]

Hey guys, i have trouble in one mission, precisely in system Dionysus, where i should escort convoy. I done that and now some pirate jumped into sector with big army and i need to blow my ship near to them to kill them. But i dont know how to do it. Pirates are stacked near portal, my battle ship cant get there in time and if i send there my fighters it do nothn. After short period of time my battleship explode and game over. I really dont know what to do, can you anybody help me pls? It would be much appreciated !

Chicken