Your questions

Strange lead

As East I open One No Trump (weak) and the rest pass. All vulnerable.

South held:

S Q5
H K874
D 965
C A872

What would be a normal lead from South and why? - CS

Derrick responded: The normal choice is the H4, fourth highest from your long suit. Two reasons:

1. Even though you may lead from an ace against notrumps, it is better to lead from a king

2. Major is preferable. West will usually not have five hearts, but may have five clubs (and for some pairs, the same holds true of East).

CS replied:

Many thanks for your reply. I was East. My partner and I are intermediate players. N/S were strong good players. This was a club competition.

South led the SQ.  

South had  S Q5 and North had S AK76432. I had S JT8 and N/S took the first seven tricks.