"It was a really good first half, the second half we missed some early opportunities and that let them back into the game," said Ruddock.
"With the ball in hand we looked great. We played with purpose and skill, combined with good decision making and accuracy. We didn't tackle to the same quality.
"Montpellier were a very good team and they battled back into the game. With the ball in hand they looked quality, although they didn't want to get into a set piece battle with us, that was clear."
Ruddock refused to be downhearted after his team failed to hit the same heights in the second period and admitted the efforts in the league in recent times had taken their toll.
"It's been a tough month," said Ruddock. "What we have done is really front up and deliver the goods and made a big physical effort.
"Five or six games into that there is a chance you are going to be there in terms of defence, that was the case against Montpellier.
"I don't want to take anything away from Montpellier but it was evident our first up tackling wasn't quite up to where it has been the last few weeks. That is down to mental and physical fatigue."
Warriors can now look forward to a cup semi-final and the finale in the Guinness Premiership and Ruddock admitted he would look to youth to make an impact in the coming weeks.
"It is a big prize at the end of it and we want that," added Ruddock.
"We're not out of the woods yet in terms of the league but I was disappointed that I couldn't get one or two younger players on earlier in the European game.
"Joe Carlisle has a big future and even in the short space of time he was on he made things happen and put runners into space.
"The challenge over the next few weeks and games is to try and get some of the younger lads involved and give them more of a taste."