Worcester now turn their attention to the European Challenge Cup for two weeks before a trip to face Ospreys in next game in the EDF Energy Cup.
And Ruddock has urged his players to now build up the pace before a return to league action in November.
"What we have to do is use this competition to build momentum and the same with the European Challenge Cup, that way we can build confidence before the next round of league games," said Ruddock.
"London Irish are a proud team with a good record defensively and they were never going to lie down. We were hoping to put them away earlier in the second half but they went back at us very strongly.
"But what was more important for us was that we kept focussed on our defence. We felt it had let us down a bit in the last few games and we have conceded quite a few tries.
"We were still disappointed to have let one in today but that was individual brilliance by Peter Richards and a strong fend from him from a tap penalty.
"We have a tough game to come down at Swansea against the Ospreys, that will be a big one but if we can play well and get a result there is a chance we could progress in the group," added Ruddock.
"They beat us up here last year and we haven't forgotten about that. I guess we have a point to prove when we go down there in a few weeks time.
Ruddock was full of praise for the young guns that fired in style in the cup and Miles Benjamin who grabbed a brace with England boss Martin Johnson watching from the stands.
"I thought young Kitchener is a huge talent and he scored a great try. Jake Abbott has been out injured for a few weeks but his overall his work rate was excellent. Alex Grove did fantastically well and Charlie Fellows had a run the other night.
"All the youngsters, who we feel will give us a strong squad in the coming years, did well and the more we can blood and develop the stronger we will be for it.
"It was great to see Miles (Benjamin) get back on the sheet. Like a centre forward in football you can go a game or two without a goal and he started the season like that, but thankfully he is now getting back on the score sheet and that will help his confidence."