However, Worcester failed to turn territorial and possession dominance into second half points and Ruddock admitted his team needed to start taking their opportunities.
"It was a game of two halves," said Ruddock. "In fairness to Quins, they played really well with the wind first half.
"We put them into bat hoping our defence would hold tight but we were very disappointed to concede two tries. We made it known at half-time and we decided to put our captain on and that gave us a real lift.
"Pat brought a huge effort with him and led from the front, everyone got behind him and he scored pretty much straight away after coming on. I thought our intent and our passion in the second half was excellent, I couldn't fault the players.
"But the execution cost us. We had a number of chances in the second half. We had a scrum on their line and got turned over, we lost a few lineouts that we could have launched attacks off and we lost them. The very last attack of the game we tried to force a play when time was up. We tried to do something a little bit radical when it didn't need to be done that way and we conceded.
"We defended much better second half, we showed a lot of urgency in the second half, we showed a lot of commitment and passion second half.
"We created opportunities for ourselves - we just were not good enough to nail them down. That is the big challenge for us over the next month or so. To defend as well as we did second half but also take our chances."
Warriors are next in action on November 14 when they travel to Sale Sharks in the league and Ruddock believes the return of some key players will give his side a boost as they look for a cutting edge.
He said: "I told the team after the game that I was pleased with the second half and our commitment, efforts and physicality. That is the standard we need to bring into our next round of Guinness Premiership games.
"But I have told them that the clinical and ruthless edge was missing when we create chances. At the moment there are teams out there that I don't think are playing that much better than us. I don't think Quins were that much better than us, but they took their chances.
"Over the 80 minutes it was a good contest but they were the better team because they took their chances.
"Given that I have got some troops coming back, people like Pat Sanderson, who will provide the leadership I am after on the field and that galvanising impact on our breakdown skills, I'm not as concerned as I would have been if that was not the case."
The result meant that Ospreys went through to the semi-finals next year and Ruddock admitted that although he was aware of the score at the Madejski Stadium he was always much more focussed on events at Sixways.
"I was aware of the London Irish and Ospreys score, I was getting messages and knew Irish were leading by a big margin at one stage," he added.
"But to be honest it was never about the other game, for us it was about trying to get the win and trying to take it down to the wire.
"At 20-14 and ten minutes to go I felt we could sneak it and we were pressing on a consistent basis.
"But our execution let us down, whether it was an over throw at the lineout or a missed scrum opportunity, we failed under pressure to nail those skills down and that is something we need to go away and work on."