The 26-year-old prop led by example with a big contribution to the 17-7 success over Greenock Wanderers and was quick to point to the performances of youngsters such as impressive winger Kyle Smith. However, he reserved his warmest praise for two men over the age of 30 who brought their big-game experience to bear.
Despite a slow start by Lasswade, one of that duo, stand-off Carl McWilliam, opened the scoring with a penalty before Wanderers enjoyed a sustained spell of pressure that yielded a self-converted try for Antony Devlin. The other, Bernie Hennessey, played a major role as Lasswade regained their composure and McWilliam kicked penalties either side of the break to edge his side back in front. A sparkling solo try by man-of-the-match Smith extended the advantage and McWilliam rounded off the victory with penalty number four.
Billingham said: "Carl and Bernie have both played at Murrayfield before and it's massive to have guys of that calibre in your side." Lasswade will look to use the victory as a springboard to promotion. They need wins in their remaining fixtures to join Greenock, who have already taken the National Division Two title in commanding fashion.
Billingham added: "It was as we thought it was going to be – tight up front and a battle in the forwards. It was all about concentrating on everything and we did that. It was about will and desire in the end.
"They were definitely the best team in our league this season. We have two games left now and hopefully we can win them and go up to National One."
Earlier in the afternoon, North Berwick had capped their fine season by adding the Scottish Hydro Regional Bowl to the East League Division One title with a win over Strathmore that was considerably more comfortable than the 13-8 scoreline suggests.
Peter Gannon touched down for the East Lothian side and Grant Craig weighed in with the conversion and two penalties.
In the day's showpiece final, Ayr saw off Melrose 36-23 in a double header that delivered the Cup for Kenny Murray's men and also contributed five points towards their Scottish Hydro Premiership title challenge.