The fastest way to win a battle is to immediately capture the Ion Cannon for your team. Capturing the Ion Cannon from the start is not only faster, but also easier as you need the Ion Cannon to take down the enemy capital ship's shields. However, if you wait too long the enemy will capture it instead and then you need to blast your way past hordes of opponents before being able to take it for your team. Once you have captured the Cannon, defend the command post until the Cannon charges. Do not leave the CP while you wait; you will most likely lose it and have to recapture it then wait again. Once the Cannon charges, use it to take out the enemy capital ship shields. If done correctly, two hits should be sufficient. Once this is done, victory is almost guaranteed. Even if you choose not to transition to space and blow up the ship, one of your teammates will eventually do it for you. If you want to do it yourself though, sprint past all of the enemies in the hangar and in the walkways. Do not worry about shooting them, as they will just keep respawning. You will eventually get to the room with the Reactor. Keep throwing grenades and shooting at it until it disappears, and the ship is done for.