To do this you'll need a teammate with stealth and a juggernaut(Or the republic equivalent) that has the skill 'intercede'.
1. Have the player with stealth go to your team's goal and have him camp there.
2. Have the juggernaut get the opposite team's ball have him run back to the stealthed player.
3. The juggernaut needs to target his stealthed teammate and use the skill 'intercede'.
The skill intercede is instant, with a range of 30m, so you have a pretty good distant to jump.