After starting their season with impressive victories over Bridgend and regional rivals Llanelli, the Quins had too much for Aberavon on Saturday despite the Wizards being in fine form themselves.
Tonkin, who is in charge of a much changed squad, was understandably delighted following a third consecutive win.
"We have lost a lot of players and brought in youngsters and it is going well," he said.
"There are boys like 18-year-old prop Jevan Sebastian, who has just started his first Premiership game on the tight-head.
"He and several others have stepped up well and we go to Swansea next Saturday full of confidence."
Craig Evans kicked an early penalty for the Quins with Rory Gallagher crossing for the first try of the day. Paul Smithson, on his debut for the Wizards, kicked Aberavon's three points.
Evans knocked over a second penalty on the half-time whistle before Ellis Lloyd set up wing Rhys Thomas.
With a 16-3 half time lead, the Quins were always going to be tough to beat.
Aberavon attacked more after the break and three more penalties from Smithson gave them hope.
But a third Evans penalty and a solo try by centre Dylan Morgan ensured the Quins continued their dream start.