As part of my elementary patterns training* at chesstempo I stumbled across
this tactic.
The position is from
this game between Polgar and Kasparov where Kasparov misses the above tactic, which is quite elementary to even a patzer like me, when you know there is a tactic present. I like knowing that even the best miss simple stuff.
*this is just a custom set that I built for all problems rated < 1500 with average rating of 4* or better. My goal is to solve each problem in under a minute, and if I go over a minute I give up and review the solution.