A Paul Diggin try two minutes from time saw Worcester have to settle for a losing bonus point on that day after earlier taking a 17-0 lead in the game.
Ruddock insists his team should take confidence from that display at Franklin's Gardens and now must raise the bar in order to end 2009 on the front foot in the domestic arena.
He said: "Northampton Saints are a very good side. But we pushed them all the way down at Franklin's Gardens at the start of the season and we have got to take some confidence from that.
"You have to give credit to Saints, they are often the masters at coming back at you and if you don't play for 80 minutes flat out with huge intensity they will beat you.
"We played well for 50 to 60 minutes down at Northampton on day one, but we dropped away and they came back at us and got that try.
"We are aware that they are a very dangerous team. Last season they beat us on home soil at the end of the game, we had a chance to take it until they broke through with a switch play and came back inside a tired defence.
"They won't lie down and they won't give up. We know we have got to be better than we have been in the last couple of games against them.
"It's a huge task. Saints have a talented team and are used to winning, they will see themselves as favourites going into this game and the league table tells us that.
"We have got to get stuck into them and the players will really be up for it, we know how big this game is for our season and the time is now to produce."