Veteran Craig Beasant added a third touchdown before further tries flowed from wing Paul Songhurst and a second from Howe. That made it 27-3 at the interval and with the home side employing passive scrums for the second half, there was no further scoring.
Last year's beaten finalists, Rhydyfelin remain on course for another trip to the Welsh capital after a 38-3 win at Penarth, while Whitland edged out Crymych on try count after a 13-13 draw.
There will be no giant-killing for St Peter's this season after they were well-beaten 29-0 at Parc de Pugh by a Brecon side struggling for form in Three South East.
Brecon took full advantage of playing with the wind in the opening period to go 10 points up in the early stages thanks to a try by full back Gwyn Pengelly and kicks from Gari Davies.
Pengelly was in fine form and his pass to winger Ryan James led to a second try again converted by Davies. The first half scoring was completed by a forward drive on the interval for hooker Jake Powell-Thomas to dive over.
In the second half, the Rocks changed tactics by keeping the ball in the pack, but Brecon held firm and Davies raced clear for a solo try which he converted to complete the scoring.