Most intense battle I have ever had just now:
All my team is dead, except a level 32 magmar. Kingdra has like, 20 hp left. I hit him with one faint attack, he is down to like, 5 health. He hyper beams me, I have 3 health left, I hit him once more with a faint attack and I win.
I was pissed when he hit me with hyper beam and I thought I lost, then I was like 3 HP WTF! :O
tl;dr: I killed kingdra with magmar.