Uruguay came from behind to defeat Canada 32-31 in Montevideo and qualify for next year's World Cup in Japan.
The Uruguayans, who had beaten Canada 38-29 in last week's first leg to build a nine-point cushion, fought back from 0-15 down in the first half to book their fourth appearance in rugby's biggest tournament.
Two opportunistic second-half tries from Uruguay centre Andres Vilaseca sealed a deserved win for the South Americans and sent Canada into a repechage later this year.
Uruguay will now enter Pool D alongside Australia, Wales, Georgia and Fiji.
Canada, who have never failed to qualify for the World Cup, made a dream start with fullback Brock Staller kicking a penalty for a 3-0 lead before Newcastle wing D.T.H. Van der Merwe rounded off a flowing move for the game's opening try.
Canada then drove over from a line-out for another converted score, Taylor Paris dotting down, to put the visitors ahead on aggregate and on course for a ticket to Japan.
But Uruguay came roaring back and caught Canada napping with a quick tap penalty which allowed lock forward Ignacio Dotti to barrel through flimsy Canadian tackling for a try.
France-based flyhalf Felipe Berchesi added the conversion before drilling a penalty to put Uruguay right back in it at 15-10.
Staller added a penalty just before half-time to give Canada an 18-10 lead at the break but Uruguay reduced the deficit to five points when centre Juan Manuel Cat wriggled over from close range for a score early in the second half.
Staller hit back with a penalty to make it 21-15 to Canada before Berchesi responded immediately after the visitors were pinged for a high tackle.
As the game entered its decisive phase, Canada wilted visibly, and when a sloppy pass went to ground near halfway, Vilaseca pounced and raced over from 40 metres to put Uruguay 23-21 ahead. Berchesi added the conversion to make it 25-21.
Replacement Djustice Sears-Duru drove over to put Canada 26-25 ahead with 10 minutes left, but another Canadian blunder allowed Vilaseca to scamper clear to score once again to effectively seal qualification. Van der Merwe scored a late consolation try for Canada.