St Finian's defended the gain line well. But, the pressure started to tell, two penalties coming the way of fly-half Daragh Irwin for a 6-0 lead after 12 minutes.
Then, Reamsbottom popped up in a wide channel, slipping the ball back inside for wing Adam Lynch to pierce the Finian's cover for a try, converted by Irwin, for a 13-point advantage at the break.
The next score was crucial. St Finian's had to strike to stand a realistic chance of mounting a comeback. Fly-half Ronan Wallace kicked them back into the game in the 39th minute.
However, when Gibney worked his way over from a 5-metre scrum, the game was as good as sealed. Gibney powered over for his second and Reamsbottom secured their fourth try before St Finian's centre Anthony McGivney struck for a well-deserved try well into the last quarter.
CBS Wexford also made home court advantage tell in their three-try 25-7 win against East Glendalough at Park Lane.
Wexford asserted their authority in the forward exchanges, setting up out-half Eoin Roche for a penalty.
It wasn't long before they were coming again. The forwards rumbled on and scrum-half Conor Fenlon moved the ball left for wing John Joe Browne to make the line.
Once they had momentum, they were inclined to use it. The pick-and-go was used frequently enough to exhaust the Glendalough defence for hard carrying number eight Collie Joyce-Ahearne to burst over.
Roche added the extras for 15-0 in the 23rd minute.
Wexford were ruthless in applying pressure, Fenlon blocking down a clearance to pounce for the third, Roche kicking the conversion and a penalty to take them out to 25-0 at the interval.
The Wicklow boys were not short of effort or, indeed, creating half-chances that could have been turned into points earlier than their consolation converted try in the 58th minute.
It came from centre David Hastie, who tackled his heart out and broke the gain line several times, only profiting when it was too late to make a material difference in the 58th minute.
The conversion came from the boot of fly-half Fergal Marshall as small reward for his outstanding contribution in putting players away and keeping EG at the right end of the field.