Rowan Vine's 52nd-minute strike was enough to lift Saints up to fourth in the SPL as Lomas' side deal with a heavy fixture schedule.
And with Gregory Tade, twice, and Frazer Wright all hitting the woodwork, the hosts were unfortunate not to run out clearer winners.
"The aim was to get the three points, I didn't care how we got them, by hook or by crook," said Lomas.
"We had a tough game away at Ross County on a heavy pitch and then a tough game against Celtic on Wednesday. That was three tough games in a week and we knew this wouldn't be one for the purists.
"The first goal was critical and we got it. St Mirren had to come out and expose themselves a bit more.
"They opened up a little bit and it allowed us to hit them on the counter-attack. It could have been a bit easier but for a couple off the woodwork.
"All credit to the boys, we have had this ridiculous situation with six games in 23 days and then three weeks off."