I ended up bringing 1,000 points of Eldar I had assembled for my LGS's tournament, which almost didn't happen for a second month in a row. Players 3 and 4 showed up about 10 minutes before game time, just in time for the organizer to not call it. For my first opponent, I drew Tyranids.
Turn 1, lacking any real range or line of sight to the Tervigon, I mostly moved up as fast as possible, going all out with the Falcon to get the Fire Dragons close for turn 2. The Warp Spiders revealed the objective on the mid right to be sabotaged, and thrust moved away.
On Will's turn 1, he spawned 12 gants, and ran out. The Termagants and Tervigon made for the Warp Spiders on the right, managed to kill one to shooting, loose one to overwatch and then promptly fail a 6" charge.
I continued to move up and poured fire from the Fire Dragons, Falcon, Warp Spiders, and Dire Avengers into the Tervigon, killing her off and taking all but four gants with her. Fire from my guardian starcannon kills a single gant, but gets them to run. After some quick discussion, we determine they run to the closest of the two board edges, so they run off the board.
Then, in the bottom of Turn 2, the hammer drops, with everything Will had in reserve arriving: Doom of Malan'tai, 2 x 17 Devilgants, all in pods, plus a flyrant.
The flyrant vector strikes the falcon, dealing two hull points to it. In the shooting phase, the doom soul sucks 9 of the right guardian squad, while the left guardian squad survives unharmed. Shooting from the first gant squad on my Farseer's guardian squad causes 17 wounds, which are all saved by re-rollable 3+ cover from Conceal and Fortune. The other gant squad decides to wipe out the remaining couple guardians, and does so with plenty of fire to spare.
In a brain-lapse, I allowed the flyrant to assault the Dire Avengers even though he had swooped onto the board. This pulled them off the objective and then wiped them out. Similarly, I also allowed the devilgants on my left to charged in, getting 10" on their charge, which was more than enough to allow them to contest the objective (as time was being called).
Regardless, with the game ending after turn 2, I won with a 2-1 victory, even if it should have been 8-1. That said, if the game continued another turn I would have been in some trouble.