Four first-half kicks put the Chiefs in the driving seat 12-0 at half-time in a scrappy encounter at Sandy Park, with the Dragons' indiscipline further compounded by the yellow card to scrum-half Joe Bedford.
Bedford did not reappear after serving his 10 minutes either side of the interval, being replaced by Jonathan Evans, and it was Steffan Jones who got the visitors on the scoreboard.
The young fly-half, with a first successful and second penalties, gave the Dragons hope of retrieving a 12-6 deficit but Argentine fly-half Mieres slotted two more in reply in the final quarter to secure victory and top spot in Pool Four.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
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The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
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The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.