Northampton Saints reached the Amlin Challenge Cup final by beating three-times winners Harlequins. Saints built a solid lead through two Stephen Myler penalties and a Tom Collins try, with Ben Botica's penalty the only first-half score for Quins. Saints's Kahn Fotuali'i broke away to touch down, but Nick Easter replied. Northampton director of rugby Jim Mallinder said: "It was a hard-fought win and was always going to be tough because Quins are a good side." The visitors failed to mount late pressure as Saints battled through. Northampton, winners of the Challenge Cup four years ago, now have the chance of a Premiership and European double as they head to the Cardiff final at the same time as pursuing a home play-off in the league. Mallinder added: "Defensively we were very good for 80 minutes and stopped a lot of their threats. "George North has a calf strain, hopefully it's not too bad. He picked it up in the warm-up and thought he was okay to carry on but clearly wasn't 100%. "Tom Collins hasn't been selected for the England Under-20s so they must have some brilliant wingers. He's been great for us all season. "Kahn is a special player. There were two outstanding nines on the field with Danny Care for them, but I thought we marshalled him well." Quins, whose three successes in this competition are the highest of any club, will now turn their attention to sneaking into the Premiership top four.