A few years back Farnborough (I think it was) had a good FA cup run and managed one of those classic third round upsets. They weren't even nationwide conference, they were in one of the regional leagues. So about 6 divisions below the top flight.
As a reward their manager spent part of the TV money on a week long training camp in Spain. The then England women's team happened to be out there at the same time, so they had a friendly. Farnborough, 6 divisions below the top flight, beat the England women's team.