Aberdeen' s fourth win in five matches moved them into the top half of the cinch Premiership for the winter break.
And it was a further sign of progress after winning just two of 16 encounters between mid-August and the end of November.
Quoted on the club's official website, Lewis said: "We could have played better - but conditions were terrible.
"It was a battle and previously in the season that is the type of game that we would not have won.
"We seem to have found a way to win these sorts of games. You have to stay patient. It was scrappy, not pretty. But we were professional and dealt with a lot of their long balls forward and picked up the second balls.
"They had moments, one at the end was a bit hairy, but we managed the game well and got the goals that we deserved."
The club captain added: "The points were the main thing, especially at this time of year. That is four wins out of five and pleasing that we have finished the year strongly.
"It did not matter how we got them, because we don't know what the start of next year holds.
"Hopefully we can get over the restricted crowds and move on as quickly, then we can get this place bouncing again and have a really strong second half to the season."