His effort got Jones' troops back in touch before Nic Cudd got himself over and a penalty try sealed the win.
Josh Navidi's try did make Dragons sweat towards the end but it wasn't enough and Jones was left beaming at his team's performance.
"I am immensely proud of the players and the effort," he said. "The commitment and attitude in this competition has been exemplary.
"We weren't perhaps at our best today, I think it's fair to say, but we still had too much for the Blues. It's massive for the region, a region that's bouncing back from many years of being unsuccessful.
"It's so important to the business, so important to the supporters and players.
"It was a big game for us, not just because it was a quarter-final of a prestigious tournament, but also because it's a local derby and everybody knows each other's games inside out.
"That's what you saw, you didn't see a great standard of rugby. There were a lot of nervous players there.
"Big games are about big players and the Blues had a lot of big players there and I thought that would have been the difference. We've got lots of inexperienced boys."
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