I just think Moyes weighed up the possibilities before the match
1 - Go toe to toe with Brighton = Chances of winning = 2%
2 - Low block and pray for everything to go West Ham's way = Chances of winning = 10%
Moyes being Moyes, he would have never seriously countenanced possibility 2.
But...
There was of course a massive dollop of luck involved as well.
One of our centre backs had by far the worst game he's ever played for the club
Their keeper played the best game he has played for their (and probably any) club
But more than that, if you cough up 80% possession and 35 crosses and...