Sarries continued their good form with a 37-12 home victory over their Devon One rivals New Cross.
But there was disappointment for OPMs and DHSOB, who went out of the competition. They will now go into the Devon Vase.
OPMs lost at home to lower league Buckfastleigh 29-17, while Devon Two side DHSOB did give Devon One outfit South Molton a run for their money before going down 44-22 away. Old Techs, meanwhile, were unable to fulfill their game against North Tawton.
Saracens will play Buckfastleigh in a two-legged quarter-final, with the first game pencilled in for November 28.
The Ernesettle-based side have already won the Devon section of the RFU Junior Vase and they are hoping to go all the way in the Devon Junior Cup.
But, despite their five try to two win over New Cross, coach Stuart Busfield said his team were disappointed with their display.
“The boys were disappointed with the performance,” he said. “We did not go particularly well but at the same time we still came out with the win.
“You have got to look at the positives, even though there were plenty of negatives.
“The one real positive for us was our defensive line-out. Arran Webb stole about seven line-outs.”
Winger Jamie Lavill-Harris had a big game for Saracens, putting in some big hits and scoring an impressive try, while scrum-half Tom Rigby again impressed.
Rigby also got amongst the tries, as did Marc Cioffi, Karl Andrews and Lewis Brown, who had been promoted from the second team.
Meanwhile, DHSOB director of rugby Mike Freeman felt South Molton’s 44-22 win flattered their hosts, who last year were playing in the Cornwall/Devon League.
The Old Boys, although struggling in the line-out, were only four points behind midway through the second half but just ran out of steam after having three players sin-binned during the cup tie.
“I do think the scoreline flattered South Molton,” said Freeman.
“We got close, but not close enough.
“The difference was their organisation on the field. They were very well-drilled and had a very tight front five, who won them the game. They did dominant the line-outs.
“We were very competitive for a good 60 minutes, it was just that last quarter. They got two late tries that put a gloss on their victory.”
Although DHSOB have plenty of individual brilliance with the arrival of a host of the Plymouth Fiji side, Freeman admits they still need to work on their line-outs, scrums and ruck work.
Meanwhile, Saltash were knocked out of the Cornwall Senior Cup at the quarter-final stage by losing 15-10 at Wadebridge Camels.
The week before Saltash had beaten the same team in Western Counties West. Ryan Cruickshanks scored the Ashes only try.