And We Run

Let's use the Alcubierre warp drive as a basis for Star Trek's warp drive, where the ship's warp field catastrophically collapses the space in front of the ship and catastrophically expands the space behind the ship at faster than light speeds since unlike starships, space itself can travel faster than light.

With that, when the Enterprise's warp drive was expanding space behind it, the Vengeance's warp drive was collapsing space in front of it and the space the Enterprise had expanded, thereby the collapse and expansion cancels each other out forming a pocket of normal space between the Enterprise and Vengeance, which is then carried at warp speeds with the 2 ships.  And it's within this pocket that allowed the Vengeance to unleash its deadly arsenal onto the Enterprise.

Plus when the a Enterprise slipped out of its warp field due to engine damage, it fell into said pocket that protected the Enterprise from being torn apart atom by atom from the FTL/sublight speed differential, and the pocket of course dropped to sublight and disappeared when the Enterprise's warp field dissipated.

and like beaming onto the Borg cube on The a Best Of Both Worlds, it's a good idea to be within range and matching warp speeds.