Sad but true. A single solitary ship, unsupported, attacking a tactical cube and winning.
As SF Debris would put it "That's it. I'm getting too old for this."
But, VOY didn't win. In fact, the first time it went up against that tactical cube, it ended up with some damage... and this was a carefully planned mission (probably extra attentiveness went into making sure the Warp drive wasn't damaged) for the sole purpose of getting their away team with a virus onto the cube... and the mission resulted in the loss of the Delta Flyer too.
Second attempt went bad: VOY ended up with a hole in its saucer thanks to Tuvok being assimilated (though, Chakotay should have altered all the command codes the moment the away team left the ship) and both Chakotay and Paris rushing into trying to extract the away team.
Third attempt had the VOY being assisted and augmented by a friendly Sphere with disconnected drones from the Hive mind... and even in that battle, things were at a standstil (or should I say, some minor damage was done to the Tactical cube mainly because of the Sphere being able to deliver quite a few punches)... however, it was only after the queen ordered the self-destruct of the cube that VOY was able to beam back its away team... so, no, it wasn't really a victory per say.
The Queen wanted to kill Janeway, so she went to the extreme lengths of destroying a very powerful ship at her command in an attempt to do so.
We also need to bear in mind that by this point, VOY had numerous augmentations installed... aka, from One (the future Borg drone that was a product of Doctor's EMH, Mulcahey's DNA and Seven's nanoprobes).
Its possible this was one of the larger 'turning points' for VOY's tactical ability to resist Borg ships... or at least, offer 'some' resistance.
Yes, I know, its still one ship, and shouldn't have really been able to go up against the tactical cube in the first place.
I think a weaker showing was in 'Dark Frontier' when Janeway entered the Queen's chamber and the drones slowly approached her, but then progressively stopped when she threatened to destroy the chamber with high yield torpedoes.
When the Queen finally ordered her drones to assimilate both 7 and Janeway, 7 takes a good chunk of time to tell Janeway where to fire (at this point, the drone approaching JAneway should have been able to assimilate her several times).
That and the Flyer's ability to resist Borg torpeodes was quite impressive... though in fairness, that WAS in Transwarp, and its possible all kind of interference would have prevented a stable lock (what with 7 assisting - and it looks like the Queen's Diamond didn't want to destroy the Flyer because they were trying to use a tractor beam on it).
VOY destroying the TW aperture with torpedoes (which destabilized the conduit and subsequently destroyed the Diamond) on the other hand wasn't all that bad.
Its just the Flyer was able to escape the Borg stronghold much more easily than I thought was credible.
